Just like ATM machines make the user take his/her card back before
dispensing the cash, (guess why),
the blue reply button should not become blue, before the user has
finished his edit (or explicitly clicked the “x”).
Also, the user is busy flipping back and forth windows and answering
phone calls. When he flips back here he tries to recall what he was
doing. At first glance it looks like he is in the middle of posting a
reply.
"But then he thinks “didn’t I already post this?”
“Oh, I see, I was editing the title.”
The UX should do it’s best to get him back on track, and not assume
users stay fixed on the same window until a task is complete.