I've always felt that the "that armor's too strong for blasters!" and then the explosion creates a continuity error and no EU explanation has really satisfied me. I know Ady plans to make it apparent that the 'neck' section has been damaged as is vulnerable, and that's better than the way it is now, but still it's destruction leads to other problems: If the At-At has exploded, there's no reason for the rebel troops to leave the relative safety of their trench only to be gunned down by the other approaching walkers.

I'd really like to see an edit with the At-At explosion cut out. I'd rather the scene play out with the walker tripping and going down, then cut to "Wow! That Got Him!" and "I see ya (whoever he says) nice work!" then cut to he rebel troops in the trench and "C'mon!" as they scramble out into the battle field to take on the Imperial troops jumping out of the downed At-At.