It's not whether or not you take their advice; it's whether or not you have the full understanding and knowledge they've accumulated over the years; it's whether you can justifiably speak with authority on such matters. From what you've already said it's apparent you don't and you can't.
yes your right, I only have two years of professional experience but do you think I'm impressed with your 16 years of experience? hardly. I work alongside designers who have more than twice as much experience as you, one of which was the former president of ACIDO and adviser to the committee responsible for developing the legal contracts which protect Industrial Designers, I think I'll take their advice instead.
I'm guessing you took some time to ask some questions of your boss or some truly senior, knowledgeable individuals. Never saw that clause, huh? And had someone explain product liability insurance, eh? Good for you. You've learned something in this exchange.
And to answer your question directly because you can't seem to read between the lines, by retaining native files you are protecting yourself by ensuring the design is developed exactly as you intend it. Like I said ultimately you are liable, yeah that clause you refer to in your design contracts is little more than a deterrent from someone sueing you if your products fails for whatever reason. Why do you think all designers who are member of ACIDO are covered with PRODUCT LIABILITY INSURANCE. It wouldn't exist if your legal garble was completely effective from preventing someone from sueing you.
Now, to continue.
First: Liability - if it becomes an issue - is determined by the courts. So your blanket statement "you are liable" is false.
Second: the need to protect/retain native CAD files because of the fear someone will make a change to the tooling documentation, primarily applies to a full-service industrial design and engineering firm taking legitimate responsibility for the part coming off the line, OR an industrial design firm advertising itself as an industrial design and engineering firm assuming responsibility when there is prudent reason not to do so. In the latter case, handing out native files is absolutely a dangerous activity as it exposes the firm's possible lack of engineering credentials which could result in a devastating lawsuit.
The assignment of responsibility is most often recorded in the contractual agreement (there are exceptions; such as verbal contracts ala "Oh yeah, we can give you CAD files you can tool these parts from"; in which case the plaintiff would need to prove you said what they're claiming was said).
Third: Industrial design is not engineering.
Industrial design hands off to engineering and then the industrial designer works with engineering to ensure "the design is developed exactly as you intend it" ... within engineering and manufacturing constraints (among other things).
Are you a professionally licensed engineer? No.
Are you, as a typical industrial designer with only two years experience, qualified to personally and directly oversee the engineering and tooling of a part, and in a legally binding fashion approve such work and take full responsibility for the product as manufactured? No.
Should you, as a typical junior industrial designer, personally have the final say in the product as manufactured? No.
Ergo, liability should not fall upon you, the typical industrial designer.
As in most things, there are, of course, exceptions. However, they're not CAD documentation exceptions. They're industrial design expertise exceptions; areas in which IDers are - after some education and some experience you don't have - justifiably considered experts in a court of law. Two years does not generally an expert make. Sorry, but someone else - the owners of the firm for which you work - are covering your ass.
Fourth: Product Liability Insurance is primarily needed by engineers, engineering firms, and those engineers responsible for the work of industrial designers. It's why Industrial Design is usually a department within Engineering.
Product Liability Insurance is certainly of use to industrial designers; especially those pretending to be engineers (and there are plenty of pretenders). It is, after all, insurance.
So with a contractual clause why does insurance exist? Because anyone can sue regardless of "legal garble". Lawsuits don't have to make sense. And neither do judgments awarded by the court.
However, just because we have PRODUCT LIABILITY INSURANCE, doesn't mean people don't sign contracts or needlessly state in them that a client choosing to make changes assumes liability. Quite the opposite; it's commonplace. And believe it or not, a well-written contract is often sufficient to prevent a lawsuit.
However, when dealing with those clients who assume responsibility without taking responsibility - and they do exist - it's the contractual evidence presented in court that's most meaningful; what you call the "legal garble"; not the insurance papers.
Simply having insurance isn't going to win a legal battle.
Being given responsibility doesn't necessarily mean you're qualified to have it. In the current economic situation, I know other designers being handed duties and responsibilities for which they're not prepared. Furthermore, if you don't refer to yourself as a "Senior Designer", why is it on your Core profile?
And yes, within two years I have already managed to position myself in an established and prominent design firm with responsibilities equivalent to that of a senior designer (although I don't refer to myself as a senior designer).
Congratulations, tadpole. You're just like a lot of other industrial designers. Now do this for more than ten years (and don't break your arm in the meanwhile patting yourself on the back).
I recently finished a project where I was responsible for the design, development, and detailing of a product with over a million dollars and tooling, and I was the one sitting down with the client pitching them on the designs I had developed. I have even brought in my own client's for which I put together the design proposals, held client meetings, oversaw the design development, and dealt directly with the manufacturer for manufacturing.
You're at the beginning of your professional education. Don't think that just because you've done this project you're at the level of truly senior industrial designers.
Good for you. However, negotiations mean nothing until the check clears.
I am also in negotiations with one of the largest watercraft distributors in Europe who is interested in investing in a design that my colleague and I designed, and have also partnered up with another designer/investor to design and develop limited edition high end designer furniture.
In the meantime, why not share with the industrial design community all the intellectual property work you did before you approached that distributor (as someone clinging to native CAD files, I assume you've behaved in the same fashion regarding your intellectual property). That's always a popular topic. I look forward to learning more.
I love it when noob designers say stuff like "hmm, I think not". It's so "I'm experienced."
So am I going to "run away with my tail between my legs", hmm I think not.