When Maverick, Goose, Ice and Slider are playing volleyball, Mav checks the time on his watch, you see the watch on for a few more shots of the game, then it's off, then it's back on and he checks the time again, gone and then back when he is going to get his shirt on to go to Charlie's house.
I did not really notice the watch hiccup. Although I can remember that Goose was not holding a volleyball when he was first trying to convince Maverick to play for a bit longer. The camera changes to Maverick. When it comes back to Goose, he is holding the volleyball. There was no time for anyone else to have thrown him the ball.