If you read the laws (see below) the player we are talking about is not 'offside' but 'out of play'.

Again, reading the law, the ref has to decide whether or not the player was INTENTIONALLY interfering with play which determines whether it's a penalty or scrum if he gets in the way. So, not always an easy judgement call for the ref.

"Penalise intentional interference 10.(g) If the ball is played quickly, all players will not necessarily have time to retire the prescribed distance.
They should be penalised only if they intentionally interfere with play – either actively or passively.
Accidental interference If the interference with play is accidental, a scrum should be formed. Interference should not be considered accidental when the player concerned has had opportunity to remove himself from the area in which play is taking place."

A player deliberately throwing the ball at or running into an accidently 'out of play' opponent could I suppose be penalised for 'misconduct' which includes "(i) behaves in any way contrary to the true spirit of the game."

That would constitute moving off the mark - and if it were properly penalised on every occasion, it would also negate the situation that the OP was highlighting.

I'm not naïve enough to think it's entirely straightforward in every case; and there should be some allowance for a player being technically in the way, but making an obvious effort to not be - am I right that in the NRL, in those cases, the DH is penalised for deliberately bringing the defender back into play by throwing the ball at him?

The fundamental problem with tackle and ptb infringements is the wild west that the ruck has become; if that were sorted out, a lot of the corollary issues would disappear - but that ship has well and truly sailed, with no real attempt by the governing body to intervene.

Its no different to releasing a ball in a tackle and looking at the ref in the eye and saying "it was stolen sir", like the penalty against SOL in the good Friday derby which was the margin that decided that match

Did it against us in GF to milk a penalty and they took the 2 but it gave us the respite we needed as we were out on our feet. The rest, as they say, is history!

PTBs seem to be quicker in the NRL, perhaps due to the influence of two officials and some more consistent rulings. It looks to be the only way out of the mess. Unfortunately we don’t have enough officials to bring this in over here.

Bellamy and Maguire have a lot to answer for. The way they revolutionised defensive play, especially at the PTB, and had their methods copied by everyone else has ruined the game as a spectacle.

Totally agree. I would like to see 2 refs in SL and see how we go. Personally i think it will make a difference for the better.