Ref reversal

[bellnier]

High School Girl's National Tournament, tight game in bad weather, where most of the match is played at midfield. I am touch judge. Ref mistakenly awards 22 m drop instead of 5 m scrum. Quick, and very, very deep, kick goes into touch...this results in a huge swing in field position and kicking team scores try a few plays later (final score 17-7, I think). This is a bang-bang sequence of events; before line-out I politely indicate to ref that award was incorrect and he admits his mistake but takes no corrective action. Here's my question...couldn't the ref negate the result of the drop and go back to 5 m scrum? Is this up to his or her discretion or do Laws prevent this? Thanks.