Everybody has their own tolerance.
If am second yellowing someone then I like it to be clear cut, and the whole stadium know why, and am not having to sell or justify my decision to anybody
Nothing set in stone but I find an unlikely overall to second yellow for a minor harmless technical offence.
I am confident I can manage the situation in the clip, either vocally, or, how about moving to the player, making it clear to all and sundry that if you step into the box here am doing you, so nobody can have any doubt at all as to what happened
Without the inside knowledge of our American poster on here, we would still be second guessing what has actually gone on here.
For me, if you sending a player off for stepping into the penalty area (because although as a referee I know thats not the case but thats how it will be viewed) , after 17 mins of the game, then you are going to have issues justifying a warning to anyone for the next 70 mins for a tackle
"Come on ref, our man got sent off for stepping into the box but you are not carding xxx for fouling our man?"
Brings me back to something I stand by. Its one thing knowing what a caution looks like. Its another thing to know when to do it