I thought (wrongly) that when I get disconnected during combat my ship will just be a sitting duck ready to be killed. Some games do that. Also once I was auto-docking at an outpost and computer tried to land me on top of some other player who I assumed to be disconnected because he did on react to my Diamondback Explorer literally humping his Mk III Cobra.
Now I know better, thanks
From the POV of the other player, you might. Same for the pad hogger. When instancing gets bad, what you see and what the other payer sees don't necessarily have to be the same. It's (or was) pretty common if, when flying as a wing in a RES, you saw your wingmates shooting at (NPC) ships that weren't there for you. Time to reset the instance then (i.e. everyone back to supercruise, then drop back into the ring one after the other on the first one's wing beacon).
But your ship is safe once you disconnect from the server (and depending on your connection, several seconds before that).
As for the debriefing - there are local logs on your system (if you're playing on PC) that record a lot of stuff. Easiest tool to read them is probably
EDDiscovery, but they're basic XML. That should get you the name of your attacker and a play-by-play record of the fight. With your attacker's CMDR name, you can try to send them a friend request and, if they react, start discussing the fight.
Otherwise, a point blank broadside from a full plasma, railgun or frag cannon ship will pretty much melt any hull. Stuffed with Hull reinforcements and Military composite bulkheads, but no engineering, an FDS will have ~4000 HP for the hull. A Krait Mk.II engineered for hull shredding (triple rapid fire pacifiers, twin corrosive MCs) will dish out an effective 460 SDPS kinetic damage. 4000/460 = 8.6 seconds until boom, if they can keep on target.