What Happened Was...

I was just watching the BBC TV stream (had to use a Windows box, my Mac can't get it). In a live broadcast from the outskirts of Basra, their correspondent Hilary Andersson in her hard-edged (for the Beeb) North England voice said: “What happened was, <pause>...” Beautiful; pure American, dragged into the mainstream, as near as I can tell, by Elmore Leonard.

I can't find any grammatical or etymological grounds on which to defend this usage, but to my ears it has both gravitas and rhythm. Which is a formula for longevity in everything from politics to the hit parade, so I hope it stays in the vernacular as long as I'm there. grep tells me that this usage has cropped up already (twice) in ongoing, and I'm sure it will again.