Lawyer: You must include my unenforceable EULA.
Anyone-with-a-brain: lol, no. Your "contribution" to this project only serves to do the direct opposite of our stated intent... Actually, why are you involving yourself here - are you billing for this?
Lawyer scampering noises recede into the distance
The minimum liability comes from doing nothing, so the default advice is "Don't."
You must be working in a very unregulated industry if that’s true!
"How do I not get sued for my new medical device?"
"Don't sell it to anybody."
In-house counsel is a little different but again even at places like IBM the lawyers could not get away with blocking meaningful business
More likely in your scenario is:
Lawyer: You must include this EULA that this person/board/committee demands, and will fire both of us if you don't, because they asked me how to cover their asses in case of XYZ.
Anyone-with-a-brain: okay.
Lawyers themselves are certainly powerful, but they only really derive power from people with real power; states, boards of directors, judges, etc.