war thunder moment :)
hmm
It looks puzzling at first, perhaps even some major desync but it's the 'discarding' part of the shell. Not sure how it causes enough damage post pen for the kill but we take those. Pretty cool I thought.
There's also a chance the rod ricocheted into the under side of the vehicle and that was actually the kill shot (not what the kill feed displays) but I find this a little less likely.