I don't think anyone is saying that, at least I'm not.
You most definitely can directly and immediately supervise someone in the field... You could certainly get an officer who was happy with you being just on the same property, or you could get one who interprets direct and immediate the way most every cop does, meaning at arms length and doing nothing else but directly supervising. How much risk you want to adopt to let someone without a PAL hunt is of course up to each individual.
I grew up hunting long before I was eligible to do it legally. I flew back with guns solo from a bird hunting trip in NB in high school. Air Canada didn't bat an eye. I brought a freaking SMLE to junior high for a history presentation. It was just as illegal then, the difference was nobody cared unless there was a reason to otherwise.
Different times back then. I sure wouldn't dream of anything like that now, kid brings rifle to school would be a front page headline.
I've been out shooting with a group of non PAL holders in a gravel pit, and the cops showed up to investigate. When it came to the first guy without a PAL, I said to the officer that I was directly and immediately supervising him. He said "yup, that's fine as long as you're right behind them and just supervising when they're using the gun." Pretty consistent with how I've always understood directly and immediately to be applied.