Please, add a check to prevent spawning "on player" and killing player this way. This can be done by TransportHelicopter for sure, maybe others.
This "spawn kill" is hard to trace, I have a plugin that disables all damage done by TransportHelicopter entity, but when it's spawned right above player and smash that player, it remains undetected. Also TruePVE log haven't detect any damage. I guess this "smash kill" is handeled some other way and I have lack of knowledge about it.
UPD:DeathNotes detects it as:
"KillerType": "-",
"VictimType": "Player",
"DamageType": "Fall"