Can Bathroom window glass crack automatically

Hi,
My bathroom window glass (Inside one) has bursted in the early morning hours on it's own.
I am having a hard time to convince my house owner that this has happened. He is not accepting the fact that it can burst.
The winows are double glazed. The glass exposed to outside is much intact no damage.

My questions to experts are:
1) Is this because of temperature deiffrence
2) Manufacturing defect (his argument windows have been installed since last 2 yrs)

How do I justify my claim.
Please help

Did it explode into little pieces or did it just crack?
If it exploded into a bunch of little pieces, this link will explain it to your house's owner. If it just developed a crack, then it's a stress crack and again not your fault. Good luck.

http://www.oldcastleglass.com/design_cr ... aneous.php

Yes it exploded in pieces for the middle portions .
The article was really informative. My landlord is going to bring expert and then I will have to put up this in front of him.

Is this unnecessary dragging too much?
what would be the cost of this replacement " window dimension is 6 x 90 inch" ?
Unfortunately I donot have expertis to do it my self? so I will be expecting the fitment.
Can some body help me in terms of estimate