I think judging a player based on one season (or in Zidane's case a handful of performances) is mad myself. I agree about you on Rio as he was consistently top class for three seasons with very few mistakes in that time but I think his point was more in reply to the idea that Rio was flawless which is fair enough really. He is painted that way so providing a handful of examples in one season is a fair way of saying that a defence with him wasn't completely impenetrable and you will get a couple of chances against him even at his peak.
The issue with that, and the reason peak form is emphasized, is that it doesn't leave level ground when a large scale of players are involved.
We have watched Rio day in day out so his bad days or errors are in our memory and on record as well. But there are players who played long ago and no one here followed them day in day out, or at least doesn't remember his bad days as clearly as say someone like Rio's, so it is unfair on recent players to be criticized for being recent, in a way. For example, had Cristiano played in the 60s or so, would anyone looking at his stats, records and highlight packages and a handful of full games years later criticize him in the detailed manner he is right now? Despite scoring goals at the rate he does he's called upon for not helping defense or not being creative enough, etc.
For that reason and to put everything on a level field I personally ignore these rare blips despite being well aware of it, because otherwise it is just unfair for me.
Also as I said earlier in this thread, unless you are actually implying a player's weakness that would effect this game, it is not really relevant to bring up stuff like Danny in Zenit scored against Rio. I mean, what's the point?