Unlike with a modern shipwreck, you might well arrive to find the crew still alive in low berths.

Also, part of real world maritime law which likely also applies in the TU is that ships belonging to a sovereign government belong to that government and its descendant governments in perpetuity.

Which is to say: "The crew of that Tigress likely has their passive sensors rigged to start waking them up if/when 'help' arrives . . . and even if you win, the Imperium is going to want its ship back, so nobody in their right mind is going to help you try to keep it."