This was Texas high school football, and, in a crew of 5, the wings are supposed count the number of players for the team on their side of the field when they are on defense, and get concurrence with the B.
I think what TxMike is wondering about is the possibility that #3 departed the field, which would mean that he would not be eligible to participate in the next down.
However, as I see it, the L stopped the game before #3 actually got off the field, and, the interruption in the game was an erroneous one on the part of the crew, so I would allow #3 to participate in the next down.
Of great concern to me is the fact that the crew allowed the coach to get way, way out on the field during this sequence. Somebody - SOMEBODY - needed to respectfully notify this guy that he needs to get off the field. They’ll get this worked out, and let him know what is going on. OK, so the L and R are busy sorting things out - although they could certainly stop a moment and take care of the coach issue. But what are the B and U doing? Get over there and help out.
Heck, since they are responsible for counting the offense, the U and the R ought to know the player count, and should have told the L, “No. We got this. They only had 11, and #3 was - for some odd reason - attempting to depart.”
Now, the L can be aware of #3, and, if he steps back on the field just before the snap, and A runs a hideout play - bang - he, and hopefully the R and U, can make the call for the UNS. At the very least, #3 would be guilty of illegal substitution, which the R, U, and L could all get, too.
Thankfully, none of that happened.
Hmmm. I wonder if the L saw a potential hideout play coming, and used the player count ‘confusion’ to prevent the UNS? That would get an 8 in my report. If that happened.