[JRutledge]

I am looking at the casebook and your references (The 2008 National Federation Football Casebook). There is not one comment about "3 seconds" in this book under those references.

And under reference 3.7.1 Situation B, Comment says:

"In a related situation, if the covering official's count of the players has determined there are more than 11 prior to the snap, a dead-ball illegal substitution foul should be charged since a replaced player(s) did not leave immediately. However, if the official's count is not completed before the snap is imminent or if the subsitutiion has not been monitored, it becomes illegal participation at the snap if more than 11 are in the formation. Each team is responsible for substituting legally and for replaced players to leave immediately as required (3-7-4; 9-6-4c)

This is not my commenting on the rule, I just quoted it. That sounds a lot like your situation. There is absolutely no reference to “3 seconds” constituting the term “immediately” in making a substitution.

I do not know what rulebook you are actually looking at, but I quoted the actual casebook.

Peace