Three well intentioned cameraman have drowned in last 15 years, trapped by their home made harnesses, 1 x fixed wing 2 x helicopters ( 1 x civilian 1 x military)
In all cases they were the sole occupant who perished.
A common mistake is to use climbing gear, carabiners are designed not to release when under load, which screws you if you are left upside down in a rollover.
A one hand, protected, quick release is ideal.
Mickjoebill