BTC and TRC addresses and keys are the same. When he "sent my bitcoins to a TRC address", the transaction was recorded on the BTC block chain, so he actually sent them to a BTC address. TRC was never actually involved in the transaction. Remember that coins actually reside in the block chain and not in a wallet. BTC-e probably believed it was impossible to fix because they looked at the TRC block chain and found no transaction. However, since TRC addresses and keys are the same as BTC addresses, all BTC-e had to do was to get the private key from the TRC wallet and add it to the BTC wallet in order to access the coins in the BTC block chain.

I hope that explains it.

I think the whole story is interesting. I'm glad it all worked out.