John Stamos looked terrified.
Well at least I think it was John Stamos. I'm 95 per cent sure. But it was one of those celebrity encounters where for the sake of a good story it actually pays to not look back.
Besides, I had the rest of an illegal u-turn to complete and as much as I wanted to stop and apologise for almost killing the former Full House actor, I had a Prime Minister to catch and two hours of excruciating traffic jams to negotiate.
Such are the joys of travelling in Los Angeles without a Secret Service motorcade.
Of course, traffic jams weren't an issue for John Key, and with his exclusive studio access I was seething with envy at his prospects for some big-name celebrity spotting. The bright lights, the big stars. I waited for anecdotes of wine and cheese with Brangelina, canapes with Johnny Depp. Given it was official business, I figured John Key probably wouldn't even have to shell out for a Hollywood Star Map.
As it turned out though, on his Tinseltown tour the Prime Minister played his star-spotting like an amateur.
For the first day of his trip, he seemed more focused on meeting Hollywood suits than Halle Berry. At the Sony studios yesterday, his motorcade sped off so quickly, the Prime Minister blew right past the Ghostbusters car without so much as a second glance.
Indeed it was only on his tour of Disney that the Prime Minister hit the Hollywood big time.
Mark Valley. Who? THE Mark Valley. Who?
No less than the soon-to-be-star of Disney's Body of Proof. Hair perfectly set, chin sharp as a switchblade. The PM's aides were naive to post a photo of the pair - they surely could've sold it to the Hollywood press for a cool five figures or more.
"PM of New Zealand visits #bodyofproof set," Valley told his Twitter followers. "Now would be a good time to invade."
I wondered if any other movie star meetings could possibly outshine such a celebrity encounter.
"Did you see anyone famous today?" I asked the Prime Minister after his final studio tour, while he lined up before a plasterboard sound stage that apparently once featured in a Smurfs movie.
"Oh yeah. Did you stop and talk?"
"Nah, he was just walking past."
Good story, I thought.
But that's nothing. You know, this morning I almost killed John Stamos.