The handsome duo was shooting a chase scene in a high-rise Vancouver car park for noir thriller, Butterfly on a Wheel when Brosnan lost control of their Range Rover and ploughed into a wall.
Butler (41) fractured his neck and shattered two ribs, while Pierce walked away relatively unscathed. And for the hunky Scottish actor, who stars in new romantic comedy Playing for Keeps, he's still paying a price for the dodgy driving
"Pierce ended up driving straight towards a wall and didn't apply the brakes in time and smashed right into it," Butler explains. "Initially we were fine, but I quickly realised my neck was out, my ribs came out, pretty painful stuff.
Fortunately, the ladies' man, who's dating Romanian model, Madalina Ghenea, is taking things a little handier in his new flick, Playing for Keeps, where kicking a football was as dangerous as it got.
Butler plays a retired football player, struggling to reconnect with his estranged son and ex-wife (Jessica Biel) in America.
And what better way to make amends? Coach his son's football team, where he encounters a string of sultry, lust-driven soccer moms including Catherine Zeta Jones and Uma Thurman.
"When you see a line-up of co-stars like that, it's times like this when you really like your job I had a ball with this movie."
And after his dire Irish accent in PS I Love You, Butler is once again, taking a stab at our brogue in Movie 43, out next month, where he'll play a foul-mouthed leprechaun.
"Well I sounded like a leprechaun in PS, why not give it a go for real," he snorts.
"That was literally one day on set and I keep forgetting that I did that film but I can't wait for the reaction. It's either going to be a triumph or a disaster."
Playing For Keeps is in cinemas