Illegal Pitch / Explination

[Bandit]

Open Question ??? While umpiring a 10 & under Tournament this weekend I called a illegal pitch and while walking to the pitching circle to explain to the pitcher what I called the defensive head coach also walked out to hear. Nothing unexpected. But at the same time the offensive coach headed out, wanting to hear. This was new to me, I had never had a offensive coach come out. I asked him to please return to the side line and that I would come over to speak to him after I had spoken to the pitcher and her coach. He wasn't real pleased with that request. After speaking to the pitcher / coach I then went to the offensive coach and gave a quick explination of what I called. Anyone have any thoughts on my actions or what I might have done. Perhaps point me to a ruling concerning offensive coach coming out onto the feild during this type of time-out?