simple tide
My dog is a retriever and Expert Hunting dog using pointer mode. I can't replicate, but every so often after using my dog to retrieve it will get 'stuck' in a loop - searching, nothing to retrieve, searching, nothing to retrieve ... and I can't get it to stop except by kenneling her and bringing her back out. No other commands will register. I can't get her to heel or point, or stay/sit/lay down.
Not a huge deal and I can't find what circumstance triggers it ... yet. I'll keep watching.