The finer points of the rules is always an interesting question.
After looking in the sporting code and local procedures, still seems like a good call. It will be interesting how the fires affect the rest of the tasking.

In the FAI rules, there are words which permit using local procedures to augment the FAI rules. These are approved by FAI prior to the contest.

The local procedures for this contest appear to have anticipated this situation and given the CD the tools to deal with it.