Based on over 35 years of working in the design and construction business, I disagree with this as a blanket rule. You try to find solutions to their problems, and they will help try to solve yours. If you think a multi million dollar building can be designed and documents with never an error or miss, or constructed and turned over with everything "perfect", you are dreaming.
I only dream at night, Bill
I work in multiple facilites where the various aspects of planning were inadequate, had errors in either written specs or the prints or both; or the contractors took it upon themselves to "remedy" conflicts without consultation with the designer, consultant or architect - and this does not include the 'make sh*t up as we go along' that is often practiced in situ. My personal belief is that construction companies exist to make used car salesmen and theatrical booking agents appear honorable... and I'm only partly joking here.
Maybe it's because I work mostly in the concert and live TV sides of entertainment, but where I come from, folks that do this kind of stuff get fired and replaced immediately because such unauthorized changes can have compounding impacts all the way down the line. It seems that in constructing facilities there are no penalties unless the entire structure fails. As a consultant I'm sure you're aware of far more cases and situations than I've encountered, but again it comes back to the question: why is this stuff allowed to happen in the first place? If it's budget, I'm crying crocodile tears for the owner - spending millions USD to build something and not paying competent people to make sure the buyer gets what they're paying for. Anything else is simple incompetence and I can't even manage fake TV tears for that.
Curmudgeonly yours,
Tim Mc