I did this once in similar circumstances. Cat tends to come to me when she wants to burn off energy and has a habit of hunting my poor unsuspecting arm or foot, so I'm not averse to a few (hundred) scratches.
Flea treatment time generally goes fairly smoothly. I hold her down gently, DP applies the treatment, and then she glares at us for a few hours from a distance.
This time though for whatever reason she went nuts. Bit me really hard, so I let go and then she turned round and started absolutely going for my leg. Got her claw hooked in and stuck, was really really painful. I had to pick her up to get her claw out of my leg, while saying "Oi" really loudly. (Which she usually understands as "You're going too far" when she's playing). Made no difference, and she starts going to town on my arm.
At which point my instincts just decided that this animal needed to be as far away from me as possible, and I underarm lobbed her across the room. There was no thought involved, I didn't think "I'm angry, I'm going to throw this cat", my lizard brain just went "need distance from this danger" and took action.
Luckily didn't hurt her, although she did suddenly calm down, think I shocked her. I felt guilty as fuck for weeks after, although she was over it within an hour, she'd have been more pissed off if we'd actually got the flea treatment.
If your DH is usually good with the cat @Friarclose , I don't think I could get too wound up that he acted on instinct once.