just another ref wrote... you hesitate. Then you react: "OH NO! Why didn't I blow the whistle?? Well, it's too late now....."
It isn't too late. Go ahead and blow it. A bit late is acceptable.
Agree.
Also, when a train wreck occurs, and you not sure if it's a block, or a charge, guess, and then really sell it. If you're wrong, it won't be the last time in your long, and distinguished, career that you make a bad call. Train wrecks need a whistle.