I was watching the rd 5 derby tape yesterday (and very good viewing it was, too

) and was sorta keeping an eye on some of the dodgy decisions. When you see a really blatantly bad decision, the general cliche is that 'they missed it'. Except, in at least two of the most blatant non-calls, Judd's clear holding-the-ball and Pavlich's choke hold on Kerr, if you watch the replay, the umpire is actually in the correct place- there is no way they possibly could have missed it.
In the latter example, Pav is on the ground next to Kerr, and he puts an arm around his neck and actually flips him across his body- so basically, he executes a judo throw via the neck- I think Cometti called it a 'almost a submission maneouver'. Okay, no worries, these things happen in footy, free kick. Except there wasn't. In the close up shot of it, you can see the umpire crouched in classic 'play watching mode', looking directly at Pavlich and Kerr the entire time the incident happens. The only possible explanations are either the umpire saw someone get picked up by their neck and thrown to the ground, and made a conscious decision that it WASN'T a free kick. Or possibly they were just in lala land, and not paying any attention to what they were watching.
So how do you explain that? how can someone possibly be umpiring AFL standard when they either can't interpret the most elementary of rules, or can't concentrate on what it is they're looking at?