Hello Commanders!
I just thought I'd drop my own two cents in here.
The concept of Multi-crew, at its core, is about cooperation, and trust. If folk are going to troll each other, there's a limit to how much protection we can (or should) put in place.
One of gunner's abilities is to be able to fire countermeasures. Gunner can be effective at this, poor at this, or deliberately bad. Anyone who would want to go down the last track is, in my opinion, someone I would not want to Multi-crew with, or wing with.
To some degree, folk have to take responsibility for their own actions. There's no mechanical upside to this unpleasant behaviour, so I see this as different from say, crime, because the game actively encourages criminal behaviour; when folk complain that the justice system is not fair enough, we say "OK", how can we address the balance and make it fairer.
Firing shield cells repeatedly for no good reason is just an unpleasant thing to do. And I'm fairly certain it is more likely to be detrimental to the community than helpful.