A1 is set to inbound the ball, A2 sets up in the paint as A1 is handed the ball from the official. A1 inbounds the ball after two seconds to A3. A3 makes a quick entry pass into A2 who lays it up and in. I didn't call three seconds but some loud mouth kid (who was crying all game) screamed in my face "THREE SECONDS! HE NEVER GOT OUT OF THE PAINT!" After I told him he was about to get a technical if he didn't quit it, I told him I would watch for it next time.

After the game I thought about it and couldn't decide.

3 second violation - NOT! The 3 second count does not start until team A has possession in the frontcourt and this possession doesn't happen until the team A player inbounds catches the throw-in.

Don't apologize for correct calls or second guess yourself when you know you are correct.

That is what I thought. I knew the front court rule but I wasn't sure since they were inbounding under the basket they were shooting at.

That's the perfect time to T up the loudmouth. You got the call right and he continued to cry about it. Being apologetic or even diplomatic encourages more abuse.