As a person who works in IT and writes code this is an interesting problem.
I suspect the base code has been written by contractors so it won’t be looked at or even fixed until Tuesday. As the functionality for displaying details for each runner works for all other meetings except Riverton, this indicates values/parameters being passed to load the data are either invalid or unrecognizable.
My best guess is when they loaded the core data for Riverton (date, course, meeting etc..), there is a bug (leading or trailing space for example) which the rest of the code can’t interpret. The way the code is compiled, it will load as much as it can and not crash the site.
Just my opinion.