And what about the person who initiated the encounter? Where is their liability here? It does take two, after all, to tango.
What should the penalty be for the aggressor? Let's start with the act that begins the encounter: the interdiction.
Sure, interdicting a clean ship already carries a microscopic fine. This is clearly not enough. Raise that fine from 400 to 4,000,000 and you might see a bit less of this.
Now, moving on to the next crime - the first shot. Firing on a clean ship also carries a micro-penalty. This too should be raised by a factor of 1,000, and no longer be a simple fine, but now a bounty.
Damage to the interdicted ship above 50% of the hull should now be reclassified as a new offence - attempted murder, with a base bounty of 10% of the value of the target ship + cargo, and be a power-wide bounty with no time limit for this to roll over into a legacy fine. It is now yours for life.
Lastly, the offence of murder - once you've committed the crime, your bounty for this offence, also raised by a factor of 1000 also no longer expires, but you then go into a new state - when you a finally brought to justice you pay your insurance claim but do not respawn for 30 minutes per Murder offence. You will be treated to a permanent list of the names of your victims while in your limbo waiting to respawn, as a reminder of what you've done and why you've been exiled to the void.
So until there is an equal force of justice to mete out to those who give cause to others to combat log, there should be no penalty applied to those who do.
And there must be a system in place to determine, with near 100% accuracy, that the person accused of combat logged did not lose power for reasons beyond their control, did not lose connectivity for reasons beyond their control, and did not encounter a system or software error for reasons beyond their control. And there is only one way I can think of to do this: Every single person must have a camera pointed at them the entire time they play to monitor their actions and ensure compliance. Anything else is purely speculation and thus unreliable.