I’ve had it happen when playing on standard definition more than a couple times, but never on a HD set, from what I recall. Could be a picture downscaling issue.
Really, it could just be a pixel difference or even less than that… Like how someone’s life bar is completely gone … not even a spec of yellow shows up on the bar… Yet they still have life. At least that’s what I’d think the problem is, I have had that happen to me before though.