User blog comment:SomeoneYouUsedToKnow/SYUTK's V4E2-Remembrance Impressions/@comment-4010415-20161101170016/@comment-25936766-20161101223213

Mmmm.....wait....no. We've been going at it the wrong way. Bandits attacked first, the Grimm came later.

The symbol could well not be a hoofprint, but the symbol of the bandits. Recall Nora and Ren's expressions when they saw that symbol.