I'm not sure about that. I think he was extremely vulnerable and emotional after losing Paula, a woman who he had a "thing" with and who became a friend. I believe he "thought" he loved Jeanne, but he didn't really. (Okay, I hated Jeanne, but I swear that's not why I believe this).

Now, your last paragraphs is dead on. If he was just dating the woman and didn't have to stick around no matter what, her behavior with her ex and the whole panic-stricken phone call because her place was going condo IN A MONTH... then going from sharing an apartment to BUYING A HOUSE... well, Tony would've been gone in a heartbeat.