Any action taken should aim to: punish the offender, protect the public, prevent it happening again and put the victim in the position they were in before the offence took place.
Is this person insane? I would assume unlikely as they have been: employed, trained and operating as aircrew. Any consequences therefore justify punishment of some sort.
This act has demonstrated this person is not suited to working in a public safety related environment. They should therefore never be allowed to work as aircrew again to protect the public from them.
Any punishment metered out should aim to deter anyone else, public or crew from doing this, so preventing it happening again.
Punishing this offender therefore, in my view, does ‘make a whit of difference’ as you put it. Also having ‘his liberty restricted’ is a punishment.
They should be made to ‘put the victim in the position they were in before the offence took place’ so of course they should pay compensation to the company of, at the very least, the cost of the slide.
And lastly they should be made to pay any subsequent court costs.
I can see no excuse for this behaviour.