shampers

they're not bright, but either the Observe camera is bugged and not spawning what they're shooting at or it's not spawning it for them either and they cannot physically shoot the radiator, so at least this time i think they aren't 100% to blame here

Railjack Pilot NPC is only capable of destroying radiator if you return to the ship. While you are on the object (in this case Shipkiller Platform), if you Observe them in the Tactical Menu they appear to shooting an object that has despawned (the Shipkiller Platform). Then as soon as you use the Teleport intrinsic it spawns in and they are able to destroy the radiator.