Yes, I've seen it happen, twice.
Once about 10 years ago I was running a 35' charter boat. We were drift fishing about 40 miles offshore and accidently bumped a large Hawksbill with the boat. The turtle got furious, roaring like a lion and chased the boat. I stopped so everyone aboard could watch it. It swam up to the boat and bit it on the port quarter chine. Roaring the whole time. Sucker has teeth like 20 penny nails! It punched 2 holes in the side and 2 holes in the bottom with one bite. Good I carried a collection of wooden plugs!
Second time was last week in Belize. We were close to Hol Chan and came up on a hawksbill. The guide stopped so we could see it, The he says "wait, I catch for you". He bails out the boat and chases the turtle around for a minute and comes up riding his back. I was thinking of my previous mentioned encounter. Well, he rode the turtle around for a minute and the turtle started roaring and hissing like previous mentioned. When the guide turned lose, the turtle turned on him and started chasing him around, and around,and around, with apparent intentions of biting his head off. It took the guide several minutes to shake him and get back in the boat. If he had been any less of a swimmer, I don't think the story would have a happy ending!