The teeth are on the back of the lever, you should be able to pull off the plastic and check the spring for the clip that locks it into the back of the handle.
e-brakes rust to the hubs if left outside for a while. If it had frozen to the hub the ice would have broken off after a few feet. One thing you can do is roll around and lightly pull up the e-brake to clean off anything that builds up... should prevent it from sticking for another 20k miles or so before more crap gets in there.