Can be a risky thing assessing another rider by their bike or kit. I'm with Ritch - passing another rider is nought to get excited about.
This thread reminded me of a mate's tale from the Adelaide Hills a few years ago. This bloke is a decent rider, and does his fair share of time in the hills. One weekend he's out climbing in the hills west of Adelaide, and some old bloke wearing jeans and a flanny shirt passed him (and dropped him) on a rusty old clunker bike.
He couldn't believe it, but when he mentioned the incident to other Adelaide locals they'd seen the guy before and knew of him. Can't recall exactly, but he might have been a former top-level rider himself, or the father of a top-level rider.
It was quite funny to hear the story relayed anyway.