I see both sides of this argument, it really is a tough one.
But Midean, you seem to be confusing workplace law and criminal law.
You talk about your opinion not being your "point of view, but the law".
This is not right. Your opinion is very much your point of view.
The law (criminal) is innocent until proven guilty, and Jack has not been denied this any way - that is why he is not currently in prison.
What the NRL has done with Jack is a matter of workplace law, and people are stood down on full pay pending investigation regularly. Jack's age and occupation make the potential negative hit for him bigger than others, but that is a matter of circumstance and doesn't change what the NRL is allowed to do.
My thinking on this is that the NRL has made the "least bad" decision of the available bad options. I don't see the NRL as having a good option here, and failing to take it.
I also think the NRL has the right to do what they did, under law, but all of this really is just my point of view, and yours is yours.
If Jack is found not guilty and he sues the NRL for something, then good on him, but that in itself doesn't make what the NRL did wrong.