I'm not sure if it's a "known bug" but I can certainly confirm that it's happened to me and my friend. In both ways around. First was me trying to revive him and I experience the same thing. His red cross became the usual blue icon but he stayed on the ground. Not long after that he revived without problems.
Later it was the other way around and he was unable to revive me. I think this may be about who joins who and as we end up switching so much I can't say if there is a pattern, it's happened twice to us.