Again, maybe rare, but they happen. Just last season, I had a fumble recovered not only beyond the spot of the fumble, but by a player other than the fumbler, and during a Try. My wing didn’t really recognize what was happening, and allowed the BC to advance the ball into the end zone, and signaled TD. I had to immediately, and emphatically, rule NO SCORE. No field mic, or even radios. I got my wings to come in, reviewed the play and the ruling, and the light bulb went off in their heads, and were, then, to explain the ruling to their coaches.
They happen, and we must be prepared to make the proper ruling for our rule set.