[AtlUmpSteve]

The umpire was wrong. The defensive coach was wrong and made the umpire wrong.

There are two possibly applicable rules, and neither was violated at that point.

1) 8-6-7 for failing to touch the base; must be properly appealed. It wasn't properly appealed, because on that awarded base, runners must be given an opportunity to complete their running obligations, and that opportunity does not end until either a) the runner stops on a different base (inapplicable here) or b) enters dead ball territory (didn't happen, according to the OP).

2) 8-6-19 for abandoning the base; not an appeal, the umpire must make this call if it applies. But it doesnt, the rule continues with "by entering dead ball territory". Again, didn't happen.

So, the coach tipped off the offense prematurely, and eliminated the opportunity to apply either rule. Runner should have been safe once she returned and touched the base because the appeal should not have been honored.