I am unsure of the question DI3G...
Are you mad at the mechanic that wouldn't sign the aircraft because he didn't have the parts required to do what he was signing for (a demonstration of integrity by said mechanic) or mad at management for putting him in that situation? If it is the latter, you are absolutely right.
My understanding is that at the moments the United mechanics are walking on egshells because they are getting second guessed for every part they change. That ain't good. On a car you don't change a part, not a big deal... car breaks down, garage makes money towing car back to garage to be serviced. Do it on an aircraft and the best you can hope for is to lose your license (and lively hood) and worse is the lives involved.
You want to see an unhappy group of mechanics? Watch the guys who are questioned after an aircraft goes down. There were a lot of shell shocked looking mechanics running around JFK in the aftermath of the crash of 587...I am sure there were similarly unhappy people after all crashes (Alaska air and the jackscrew come to mind)...
There are plenty of **** poor managements types out there. Unfortunately safety (especially in maint) is a balance sheet item. Its not an absolute. An Airline doesn't make any money being safer than the barest minimum required...
I always carried a credit card in my pocket to get me home at all my jobs flying as well. Fortunately it never came down to it, but I was always ready to leave in a second if I thought something was unsafe or blatantly illegal. I have been lucky in my employers, though I saw first hand what was going on at some of the other places. Saw a particularly disgusting scene at LakeCity Florida once when picking up one of our aircraft...
Cheers
Wino