Shot clock reset question.

[referee99]

This question was on an association test early this year:

The AP arrow is pointed to White. White #10 attempts a try for goal with 10 secs left on the Shot clock and the ball misses the rim. White #55 and Blue #45 both grab the ball at the SAME TIME creating a held ball.

a) White is awarded the throw-in and the shot clock will be reset.

b) White is awarded the throw-in and the shot clock will NOT be reset.

I answered (b) and the answer came back (a)!

I spoke to an official last night, and he was in camp (a).
I still don't understand his logic, which involved no team control, and SIMULTANEOUS held ball occurring.

What am I missing?