I believe no-one here would be important enough to order a salvo of nucleur warheads bombard an alien craft, even if we knew it would do anything. The creators of freespace would be taken into custody and questioned on how their idea for a game crashed nere a major city.
I'd probably be really freaked out, rub my eyes and, i dunno. But i don't think humans would manage to destroy the shaivans, and the shivans would be forced to destroy mankind because we're so certain they're evil creatures and would die to destroy them. And of course, how could the lucy crash? Unless it was blown out of control and it's entire crew eventually died.
By the way "Crashed and noone was killed" "Marines sent in have lost contact with [presumed dead]" Eh?!