yourmatesam
Desmond Connor (43)
Technically, it's not a penalty though, is it?
For a penalty to be awarded following the conversion, doesn't the offence have to happen AFTER the try is scored (eg Richard Loe/Paul Carozza)? Most of those head highs are as the guy is diving over the line, but before the try is scored. So, even if the ref were going to penalise, advantage should apply and the try would over-rule the penalty. If it was bad enough, a card could still be issued though or a warning given.
The ref may award a penalty try and yellow card if the act of foul play prevents the try being scored.
I'm not sure what the law is with regards to a try that is scored, but in the process of scoring an act of foul play is committed. I would suggest it is at the referee's discretion as to the outcome for this. Surely an admonishment at least.