It was tempered for sure. "Spider webbed" was the wrong word to describe it, shattered car windshield is perfect.
I hit the internet searching for a new tank and came across a thread on a fish forum. From what I read, certain companies use tempered glass and some don't.
FYI
In my journey to find a replacement, I came across PETCO's newest ad, and the have the Zilla 40B and 20L on sale for 50% off for Pals members. Couldn't talk the wifey into letting me bring a 40B home for $65, but I thought I'd pass the sale info along.