Are you blind, ref?

It is rare that I venture into the subject of football (soccer for my American friends). Last time I did so here was to query the (low) value being placed on Michael Owen. I'd like to think that I was proven correct when Newcastle paid a much higher amount for him, and he went on to prove that worth with some excellent goalscoring. Of course, now he's broken his foot and is out for two months perhaps proving the opposite (of course injuries can happen to any player which just questions the whole approach to valuing a player).

Anyway, I digress. Despite (or perhaps because of?) my poor knowledge of football, I was incensed watching my team (Everton) on Match of the Day at the weekend. Apart from the sending off of the goalkeeper which was highly and rightly criticised by both Alan Hansen and Gary Lineker, I was in fact more upset at the offside decision which cancelled what looked to be an excellent goal by Tim Cahill (one of 3 Everton "goals" disallowed). The commentator brushed over the decision, and it was not covered afterwards. But to me it was a perfectly executed goal, and one that should be allowed even if it isn't in the current rules. So, football experts, please tell me why it was disallowed, and if this decision was correct, why that rule is beneficial to the game of football?

For those that didn't see it, here is (my version of) what happened:

A pass from deep in the Everton half by Tony Hibbert found James Beattie running onto it clear of any opposition player. He was definitely not offside when the ball was played, and indeed the flag did not come up. On his left was Tim Cahill. Tim had also been onside when the ball was first played. Now he, like Beattie, was clear of the opposition. BUT, and this is what I hinge my argument on, he was ALWAYS behind Beattie and indeed the ball was played slightly backwards to him. Even if not, Cahill remained behind the ball at all times. According to my interpretation of the rules:

A player is in an offside position if he is nearer to his opponent's goal line than the ball unless...

That did not appear to be true in this case, and therefore it didn't matter where Cahill was relative to opposition players. Strangely, the commentator seemed to imply that by Beattie passing to Cahill, then it became offside. But unless Cahill was in front of the ball (by being in front of Beattie), then he could not be offside, is my interpretation.

So, my friends, I think we was robbed! (But we did go on to win 1-0 despite having 10 men for 80 minutes, so in the grand scheme of things, it was perhaps a minor aberration). Can anyone explain to me why I've got it wrong?

I wonder also whether we are reaching a point at which some decisions must be referred to a 4th official who can use video evidence. In this case, play could have gone on, and the goal cancelled on review.