Warning for delay?

[JS 20]

Team B makes a basket, as it comes through the net, A1 strikes it with her hand causing it to kick away. There's probably 20 feet or more of room at that end of the court. Weird setup. Anyway, she hits the ball, it goes toward the back of the gym. I hit the whistle, go to the table and report a warning for delay on team A. Keep in mind it was going to be team A's ball. Coach says "we were going to be on offense". At that point i just told the coach that a delay is a delay and left it at that.

I'm interested in if this was correct more than if it's "acceptable" or not. My rationale after the fact is what if Team A is up by 2 w/ time running down and they do this so more time can run off the clock. I guess you could start your 5 count while they run to get the ball since their player is the one who knocked it away? Help!