Tracking re-serves

[BlitzkriegBob]

I had a situation tonight that I have not experienced previously. I am R1. Team H is serving, down by about 9 points or so. S runs off about 5 points, and Team V uses a timeout. S scores 2 more points after timeout. On the next serve, S allows the ball to drop to the floor. I start to call for a re-serve, but then I am 99% sure she had a re-serve on her first serve of this term of service. Same server had two other re-serves previously in the match, so that accounts for my 1% uncertainty. I ask R2 if S has already used up her re-serve, and he does not know. I ask him to check with the SK. He talks to her for a few seconds and then tells me that she wasn't keeping track of that.

This was a MS match and this was a first year SK. Neither school used a libero so there was no LT. Speaking briefly with SK after the match, she told me she wasn't aware she was supposed to track re-serves. Timer told me she was sure the S had already used a re-serve. For the record, since I was not 100% sure, I allowed the re-serve, and V team won the point and closed out the match shortly thereafter. Is there anything more I could have or should have done?