To be more precise, strong (although not yet compelling) evidence of a significant tension between experimental results and theoretical calculations about the properties of a muon. That is not necessarily evidence of a fifth force -- yet! It could be a misunderstanding of our present theories, which is unlikely, although some of the calculations are quite tricky, and as I understand it there are several new calculations on the way that could change the picture and reduce the tension.
What's more exciting from today's talk, imo, is the fact that this result is based on just the first part of a much larger set of data. I think the rest of that data set, or at least most of it, is due to be processed and analysed by the middle of next year -- that would squeeze the error in experiment down by more than enough that if this result is anything to go by then it will be a "5 sigma" tension (which is to say a one in 3 million or so chance of a fluke).
The other thing, though, that *does* speak to a "fifth force" is that this is an anomaly with the same particle that is involved with other interesting results from the last decade or so. Put all together, it feels increasingly compelling that this will lead to something new in our understanding before too long.