[Mobhack]

HE is an area effect, and so it decides what was struck - a rear hit if shooting at its front could therefore be rationalised as a near miss that hit the ground just behind the target and splattered fragments backward and do an "up the kilt" hit from the frontal arc.

Just like AP gets confused if you are in the same hex and can give any facing hit. That goes back to the original SP1 V1 which did not allow you to enter the same hex as an enemy. That is also probably why there is the infantry assault allowed at 1 hex range, since you could not actually enter the tank's hex in SP1v1. It was either a later SP1 version, or SP2 where entering the same hex as an enemy was allowed. Also - SP1v1 may not have allowed same-hex movement of friends, either - but that's so long ago in the past I cannot really recall. Again, it was only a later version, or SP2 that allowed stacking, deducting MP for passing through.