The Brit hit the headlines for all the wrong reasons when he picked up Divine Brown on Sunset Boulevard and was caught receiving oral sex from her.
And Arnold feared something was wrong with his friend as he jetted off to Canada the day before the infamous incident - because Grant's behaviour was odd.
He recalls, ""I asked him if he was OK (because) he was drinking a lot that day... He said, 'I'm gonna go upstairs to my (hotel) room, watch some lesbian porn, go to sleep.' I wish he'd have done that.
""I landed in Toronto to... 'Did you hear what happened to Hugh Grant?' I'm like, 'Did he die?' and she (phone caller) said, 'Worse - he was arrested with a prostitute.'
""The next call was from Hugh... I'm like, '(Was it a) man or woman?' He said, 'I can't tell. I'm looking at the TV. It's confusing!'""