Just from a very practical perspective: is there anything FD can do in the first place? Alt F4 will always work wouldn't it? It's not like they can stop people from pressing a certain combination of keys.
How do other multiplayer games handle this?
Other video games that I've played where this has been an issue usually adopt the approach that the person who's connection craps out, for whatever reason, takes a loss and just has to suck it up. In the context of ED, I think the suggestion of your ship remaining in space for a fixed duration, say 90 seconds, would cure the problem immediately and people who combat log would be forced to formulate other, valid tactics to avoid destruction.
Yes, this will lead to rare occasions where peoples internet connections just happen to drop at an inopportune moment during a fight, but I think those rare occurences would be a small price to pay for the greater good of the game.
Given the state of the world and people being what they are these days, this rare and unavoidable "sacrifice" through no fault of the player will no doubt be seen as unacceptable (won't somebody think of the spaceships!) and there will be much protest and wailing and gnashing of teeth were it ever implemented.
The way I see it is that the needs of the many (and the game itself) outweighs the needs of the few (with dodgy connections), or the one. Unfortunately this philosophy doesn't seem to sit well with people in this day and age.