Wildlife officials called the attack an anomaly.
The animal was caught and tested positive for domoic acid poisoning, Todd Tognazzini, with the California Department of Fish and Wildlife, told ABC News.
Domoic acid poisoning is a marine biotoxin that is produced by algae and accumulates in shellfish and small fish that sea lions eat and can cause neurological damage.
"Our officer spotted what he believed to be the correct animal, it was behaving very strange, it actually exited the water and was in a state of stupor. It was biting sticks along the beach and actually worked its way up to a lifeguard tower on the beach, and it's metal, and it bit the base of the lifeguard tower," Tognazzini told ABC News. "There was nothing this young lady could have done to stop this from happening."