"At the Disposal"

[BoomerSooner]

We've had a number of questions about when the ball is at the disposal of the thrower after a made basket with regard to the timeout issue, but I'm going a different direction. Situtation: After A made a basket to bring the score to 55-56 with roughly 10-11 seconds to go, B just looks at the ball and doesn't make an attempt to pick it up to inbound it. I clicks into my mind that A isn't calling a TO because they don't have any, and I had a weird flashback to HS where I remember my coach instructing us not to even inbound the ball in a situation where we had the lead with less than 5 seconds. I put 2 and 2 together and realized that B had been coached to drain away enough time to put themselves in the same situation. I blew the whistle and ruled that the ball had "gotten away" from B. Now B is inbounding with 8 seconds on the clock instead of letting it run down. B's coach is furious because the ball hadn't gotten away, and I've now let A set their defense and more importantly stopped the clock. A's coach is quite happy with the situation. It didn't have any impact on the final score as B was able to inbound the ball, A fouled, B made both shots, and A missed a 3 pointer, got a tap in and the clock expired after the tap.

After the game, my partner suggested that I should have just started my 5 second count as the ball was close to the endline and could have easily been picked up by B. Both of us were against using a delay of game type penalty, so we narrowed it down to what I did or using a 5 second count. Are we missing something in the rules with regard to this? If not how would you guys handle the situation?