injury...circumstances...should i have let the play finish?

[Treeguy]

I had a situation where A1 drove to the basket, got behind it and to lean back to put the ball up and tumbled out of bounds. B gets the rebound, outlets my side (oppisite table) and I am now the trail. I watch the play as it gets past half court, look back and see A1 still OOB and holding his leg. I let the fast break finish, staying in the back court, blow the wistle and point to A1. Instead of going to his player and seing how he is, the coach comes directly to me and telling me I should have blown the whistle immediately because everyone in the gym knew he was hurt, except the dozen chearleader right next to him who did not notice it until I blew the whistle. It just shows coaches will complain about anything that will give them a disadvantage.