The Solar Bears had a somewhat similar situation play out last season, with a puck lost in the back of the netting (which I think was the cause of the whistle).
The refs looked at each other the next faceoff, realized none of them had the puck, and went to get a new one. Pucks are kept cold, so a linesman wouldn't be skating around with an extra in his pocket.
Something like that would have needed to play out in Minnesota.
The puck in Orlando didn't make its way into play. One of the linesmen noticed it during play and snagged it.