You do realise that there is a difference between a penalty try and a "possible 8 point try" right?
An 8 point try IS a penalty try.....
It just means the bloke got the ball on the ground despite foul play.
If you read the rulebook, you'll find them in the same category
There certainly are different rules in terms of tries.
Double movement being the obvious one. JH wouldn't have been penalised in the open field for what he did.
Also I've never seen a dummy half get pinged for "obstruction" after pushing past the guy playing the ball in general play, but do that in the act of scoring and it will be a penalty every day of the week.
There is no such thing as a double movement UNLESS in the act of crossing the try line. It's not a rule which gets applied differently when close to the try line. It is ONLY a rule close to the try line.
I'm not following how that helps your argument? You're saying that if someone bleeds, then there needs to be a rule that says it is automatically a penalty try? Or, if someone is about to score, you can't do a regulation tackle on them or else it's a penalty try? I'm confused as to the logic here.
Dummy half cannot touch his his own man in order to score a try. It's not a different rule when applying the same thing. He cannot use his own man as a shepherd EVER. If he were to pick the ball up, and for some inexplicable reason, barge through his own mans legs for a 1-2m gain, he would be penalized for using his man as a shepherd.
The reason you don't see it happen is because only a brain dead imbecile would try such a play in any part of the field, except 1m out from the goal line.