NFHS 5-1-1-H ball becomes immediately dead when: (h) the umpire handles a live ball…runners would be returned to the base last acquired at the time of touching
OBR may be different. Earlier versions of the rule book stated:
OBR 5.12 (b) 5 : If the umpire wishes to inspect the ball, he shall call time. If the umpire otherwise handles a live ball, but the umpire releases the ball immediately, the ball remains live; otherwise the ball is dead.
However, the 2020 rule book states OBR 5.12 (b) 5: Calling “time” and dead balls – (5) when the umpire wishes to examine the ball, consult with either manager, or for any similar cause.
I’m not sure when OBR changed the verbiage on this section of the book or for what reason. Since, it was changed, I would infer that MLB would want it to be a dead ball, but without a reference remaining in the book, we can’t be sure.