Dongle?

The rule that prohibits checking the nuts on the river last to act is a silly and illogical rule. Checking the nuts on the river does not have to be collusion. I explained it in this thread: http://blondepoker.com/forum/index.php?topic=47604.30

Looking at it from a different angle, I can see why you were annoyed by what happened; especially as you bubbled, and especially as the guy was clearly checking so as not to take chips from his friend. So it was collusion by the letter of the law. However, it's not like it was some master plan by the two of them to fleece the table through their cunning underhand ways. It really was just one mate not wanting to take chips off another mate. Nothing sinister. Now obviously those who take poker real serious will still be outraged by this since it definitely breaks the rules. But the two guys involved in this 'collusion' almost certainly don't take poker too seriously, are just playing for a laugh with the lads, and will be totally confused and bemused if they get into trouble. The question is, would you sooner guys like this continued to come play in your tourney, or would you prefer to drive them away? If you drive them away then everything will be done properly, with no grey areas and the rules rigorously enforced and followed to the letter. But you'll find that your games are not as fun (or profitable) any more since the only players who are left will be those who take poker oh so seriously. And they will all be wearing ipods.

'Serious' poker players would be doing themselves and everyone else a favour if they stopped pulling up beginners/recreational players on technicalities such as string betting, supposed collusion etc. If the offender knows exactly what he is doing and is doing it deliberately to gain an advantage, then fine - call the floor. Otherwise, let it go. Stop driving the recreational players away by being a stickler for the rules!

The rule that you are compelled to bet/raise last to speak with the nuts on the river is wrong and illogical imho. It is based on the seemingly reasonable assumption that the only reason you would ever fail to bet/raise the nuts on the river is if you are colluding with or softplaying someone, and therefore that this should be disallowed. However, this seemingly reasonable assumption is actually flawed. There are situations in tournament poker in which it would be a clear strategic error for you to bet/raise with the nuts on the river.

You are on the bubble. As the big stack you have been bullying the table relentlessly and increasing your stack steadily without ever seeing a flop. The entire table is playing far too tight as they are all trying to sneak into the money, and you have been relentlessly exploiting this. In this situation you want the bubble to continue for as long as possible, and it is actually detrimental to your EV if someone gets knocked out. The reason for this is, of course, that you are likely to be able to increase your chip stack even further if the bubble lasts longer, giving you an even greater chance to win the tournament when the bubble does eventually burst.

You have the nuts on the river. You are hu in the pot against a super short stack. He bets 2/3 of his stack. If you raise he will very likely call and will bust out of the tourney. At that point the bubble will burst, and some of your edge will go down since now your opponents will have made the money and will start to play more optimally. Therefore, raising would be a -EV play. It is in your interest to keep the bubble going longer and this is the only way to do it. In fact, if the short stack had pushed all-in on the river you should probably fold your hand. The EV you would gain from the bubble lasting longer is likely greater than the EV you gain from hoovering up the last of the short stack's chips.

Now granted, this exact situation is not likely to come up in a pure form in practice. However, variations based on its underlying principle  will definitely occur. Clearly a player who chooses not to bet the nuts on the river (or even to fold the nuts) in this sort of spot can be doing so purely for strategic reasons intended to increase his chances of winning the tournament. So the rule that this should not be allowed is wrong imho.