Elegant but incomplete. If Tseng hasn't always been a Turk with Aeris for his assignment, then how does he know her? How could he be ShinRa and not be something she'd avoid?
Author's response
It says in the game that they knew each other from before. I didn't leave any unanswered questions that the game itself didn't raise and the answers to those questions weren't within the scope of the fic.