coach ask me not to give directional signal

[roadking]

start of second half, reds ball. reds coach ask me if i had to give a directional signal at the start of the half. my responce was i would have to announce red ball before i put it in play in which i did loud and clear. 3 of reds player go down to whites basket as though it would be whites ball.the two other of reds player inbound the ball gaurded by two white player, the three other white player are down gaurding red under thier own basket, well you can guess what happened red scores an uncontested basket. did i blow this one and give red a unfair advantage. i normally make it very clear to both teams at half whos ball it is and with a directional signal. whats the proper mechanic at half?