What destroyed the StuG - bombs or cannons?

Last night whilst Hurribombing I killed a StuG IIIb (the grey one) which is all well and good, but upon pondering of the previous fact I noted that I didn't remember trying to bomb a StuG IIIb, so I had a look at the guncam from that sortie and found the following:

1: First Bomb Release



In this image from when I dropped my first bomb you can see a 232, which was the target, with the StuG in the upper right corner (near the smoking yellow one), clearly out of bomb range - so I didn't kill him with the first bomb.

2: Second Bomb Release



This is the second bomb release, which seems to be a likely candidate as the StuG is right under the sight, however I was actually aiming at the yellow tank, which can be seen in the next picture, of the bomb impact:




Now in this image we can see the bomb explosion, and also (conveniently) the silhouette of the grey StuG - which is about 60 odd feet away from the centre of the bomb explosion, which seems much too far away to get a kill on it, incidentally you can't see the other tank on account that it's under the massive explosion, but that didn't blow up - go figure.

Also the tank was static at the time, so it hadn't moved from where the bomb hit and where it ended up in the last screenshot.

The only time I actually attacked the StuG IIIb was when I strafed it after I'd dropped both bombs - by which time the StuG had moved back to a bushline (which rules out a bomb mobility kill):



So, was it the bombs, or was it the cannons?