Yes, and the position of the passing player is determined in relation to fixed ground markings, if this wasn't the case, like in the real world, direction would have little meaning.

and?

btw – that about a 9s 100m – he'd be coining it on the athletics circuit, not playing rugby league, if he could run at that pace

That's only reaslistic if the player is Usain Bolt crossed with Wally Lewis and he's running in a vacuum.

Apart from the speed of the player being totally unrealistic (even Usain couldn't pass a ball at that speed), we'll just go with this a second...

How far backwards and at what velocity would this player have to pass the ball in order for the laws of physics NOT to take the ball over the relative mark on the pitch which you would declare forward? I'm guessing pretty far and pretty fast!

The point is that passing is the only part of the game I can think of where the actual direction of movement is not necessarily calculated as relative to fixed points on the ground, although the position of the players involved relative to those fixed positions is used to make a judgement about the direction the pass may travel in.

Lets try forgetting about biomechanics and counterfactuals for a second.

If you chuck a rugby ball backwards from the window of a moving train, the momentum of the train will cause it to land a good distance ahead of where you chucked it from. Relative to the ground, the ball has travelled a good distance forward, yet you chucked - shall we say [ipropelled[/i - the ball backwards.

The same thing happens when a moving rugby player passes a ball backwards to a supporting player. He throws it backwards to a guy behind him, but in relation to the ground it has gone forward. So according to your system, we should be blowing up for forward passes when somebody passes the ball backwards to somebody who is behind them.

Judgements for offside have nothing to do with it, as the momentum of two players has no bearing on their relative position at a given point in time.

Many many years ago when I started watching the game, 63 years to be exact, the attacking line out covered nearly half the length of the field. If play was on the right handside halfway line the opposite winger in the line would be virtually on his own try line. Players were coached and taught to turn their bodies and pass not half a metre or even a metre backwards but 3 and 4 metres backwards.

This modern day game of flat lines and "flat" passes has brought about what is perceived to be unlimited forward passes but I still don't think that a referee watches the players hands every time a ball is passed. There is absolutely no way that he does that and therefore many blatant forward passes are missed by him.

What I find fascinating watching the SL on TV is how it is always the home fans who shout "forward" when it's the opposition in possession but never when their own team are in possession.

Usain Bolt runs faster than that.
Surely you can appreciate the simple physics here. Bolt starts from 0m/s, allows for a minimum response time of circa 0.15 secs, allows for the time it takes to accelerate from 0m/s/ upto his flat out speed and bingo