Sent TRX via off-chain transfer, recipient says he never got it — how do off-chain transfers actually get disputed/verified?

Made a withdrawal of 909 TRX to a TRC20 tackle, off-chain transfer, exhibits "Completed," zero charge. [Screenshot attached]

Recipient's discover stated USDT-TRC20 only, warned other belongings "could also be lost." I mistakenly sent TRX as an alternative of USDT. He's saying he acquired nothing.

Because it went off-chain, I'm assuming that handle is a Binance account — so shouldn't the TRX still be sitting there as an asset, just not the foreign money he needed? Or can a wrong-asset off-chain deposit truly go lacking/unrecoverable like their discover claims?

Curious if anyone's dealt with this actual state of affairs.

Edit:

I acquired in touch with binance help they usually additionally confirmed that the recipient is a binance account and the transaction was profitable.