So I'm having a bit of a disagreement with someone and would like to solicit some outside opinions. Background:

Motor: 1996 Nissan SR20DET (out of an automatic 1996 Silvia)
Turbo: Garrett BB T-28 (came on the motor, EBC turned OFF, boost 7-10 pounds)

The car left the shop without a blow off valve or coolant lines to the turbo (as well as huge problems with the motor like a dented oil pan/30+ base timing etc). The turbo went bad in a week and a half (roughly). The person I'm talking with says that it is impossible to kill a turbo that quick, and that it was NOT because of the lack of coolant/a blow off valve. This is in 100 degrees + days in Georgia.

The first turbo came off, and another T-28 went on. It has a blow off valve, but still no coolant lines.

Here are my questions to you:

1) How likely do you believe it is because of brutal temps and compressor surge that the first turbo went?
2) How long do you give the second turbo before it goes?