Got some wack, but yet could play on for another 2 minutes. Then when the black card happened, cross got a point, he straight away dropped to his knees. If there was a concern of a head injury, he should have underwent a proper HIA, which takes longer than 30s on the sideline. Watching it back, he was refusing to go off, but the ref insisted, only for him to come straight back on in the next break of play.
Plain and simple, it was game management, but it needs to be dealt with. It took 3 minutes of the black card away.
If the incident you're referring to is the no 3 and RON, when you watch it back, you will see No 3 hit RON first. If no 3 focused on his own game rather than sledging certain Cross players about their families and personal life, maybe they may not have ran riot in the 2nd half.