Yes , you could get hit from a dead lion fish.
The way it works is there is a small venom sack at the end of each spine. The spines are hollow, when pressure is applied to the spine the venom is injected thru the spine like a hypodermic. This is totally defensive. Watch when a lion feels threatened, they turn sideways and spread there spines to give max protection. So even if the animal is dead, pressure on the spine will still cause the venom to be released.
HTH
-Brian