Why do you think Shaw to LA is implausible? Shaw's issue in LA was with Jim Buss, who looks like will be sidelined by the return of Shaw's old boss. It seems like a perfect scenario for him actually.
The bigger issue is whether the Pacers would/should let him go. The Pacers normally won't get in the way of an assistant getting promoted elsewhere, but as bunt pointed out it's in the middle of the season. Furthermore, Vogel only has 3 assistants, so Shaw departing would have huge impact on the Pacers.