To answer in reverse order of posting here goes.
Dave M. In Quebec there are no reguklarly schedualed inspections for cars, but a yearly for transport trucks. So far the WS's we have fixed have all passed inspection(it is part of our warrenty), and yes controling multiple injectors while in a rush is when I broke the WS(it was about 100 in the shade, the black van was in the sun)
Bob, you omitted one thing(which may not apply for you but it does in the north), a cold WS with sudden blast from a hot defroster makes my crack repair stats go up. People have those nifty remote car starters, and the habit of leaving the heat controls on defrost with the fan on high, combine that with 3 inches of show on the WS, 0 deg temps, a star in the lower third of the WS, and you have a recepie for a crack. Also on a cold day(under 5f) a WS in the wind will cool down rapidly, but the engine does not, return to the car in 30 mins and the WS is down to ambient temp, but the coolent in the block is still aroud 150, start car with defrost on high(like you left it) and watch the star turn into a crack.
Starquest What you describe I would consider a break, and give the customer the option before repairing further. Yes I have broken a WS but thanks to my (bad)experiance my tech's have not repeated my error. I don't provide stat's for my ego(considering the bad stat is mine not my tech's), but as a reference for others. IE: a new tech reading here can know what to expect, if he/she is breaking one in 500, well it,s time to post a question, on the other hand if they have done 2000 and no breaks, well they are doing somethig right. As I said before the broken WS isn't a money problem but a work related problem(as Bob so aptly described possible contributing factors) I have learned from my mistake and so have my tech's, we always open the windows and let the vehicule cool down(or now it's more start the car and let the WS heat up


Merci