Hello,
me and a friend working together in a business which involves crypto currency.
This is the wrong approach, 2 people and one wallet for cryptocurrency, you never know what your friend can do with your coins, anytime.
This. You were doing it wrong.
Additionally, your friend was responsible for the money. He managed to lost it...
Hardware wallets cannot be hacked. Did he save the privatekeys (24 words) in a Gmail draft , or in any other digital method? This is the only way you could have been hacked.
Imo, there are two options:
-your friend didn't follow basic recommendations from trezor (like saving seed in Gmail)
- your friend stole your money