Crazy Fucking Videos

You're confusing HEAT with HE. HEAT uses a small shape charge to break the armor fo a jet of plasma behind it to enter the tank. Neither of which create much of an incendiary effect, it's all kinetic force. HE is just straight explosive power for unreinforced structures and anti-personnel.

Either way using the main gun at that range screams of unprofessionalism. Either there's a legit target there that could easily be handled by the aux gun, or more likely, they're just blowing up shit to be dicks. No tank commander of a professional military would ok that shot unless they seriously got outplayed by the Olympic Gold of RPG teams.