Turns out the chainsaw clutch wasn’t damaged at all. The chain brake (strap) had been set and I couldn’t see how it worked for a little bit. The strap was very thin and seated against the drum.
The brake bail apparently moves more than I thought it did; I wasn’t moving it far enough to disengage the brake. Pushed it back into position and all is well.
Cut two truckloads of limbs off the fenceline today. Little by little.