Horn Goes Off

[number 26]

ok, now that i know you don't care. team a at free throw line. down 2. 10-15 seconds left. makes first. down one. second free throw about to be attempted. shooter has ball. not yet into his shooting motion. horn sounds. my eyes follow ref as he walks to scorers table. cheers from team a fans. apparently, team a shooter shot, and made the second free throw. a mini-commotion as you can imagine, with team a's coach and referees at the scorer's table. free throw ultimately disallowed...
i don't know if whistle was blown by ref(s) at the sound of the horn. team a coach feels this is key. if the rule is play continues as is until a whistle, he has a valid point.
imho, coach instructed player to shoot free throw as ref was approaching table, as the first half of a win/win. and he deserves credit for assessing the situation instantly. had he missed, team a could claim attempt should not count.
how about if he missed, team b rebounds, team a not thinking play is live, watches team b go length of court for uncontested dunk...
as a team a fan, don't feel they were victimized by a bad call. horns happen.