During combat and with the opposing ship on bang on target I have noticed that I may get a few hits in before I am being thrown off target, the opposing ship seems to jump a few inches out of target.
I'm also experiencing something similar: when I hit a ship, it sometimes gets "pushed" quickly to one side.
This would be expected, if you happen to destroy a subentity. So it wouldn't be your lasers, but the partial explosion of the ship that pushes the rest of the ship away. Happens for instance if you shoot off one of the nacelles of an Imperial Courier.
Now that makes perfect sense!
BTW, I noticed that the hard ship that I originally meant was the Scoundrel (found inside [wiki]Pirate Clan Blitzspears[/wiki]).. but the mugger is not much nicer, either.