How about placing a "token" (an unplayable, and therefor invisible, item) into the Actor's inventory when you first detect they are crippled? Then you can add that check to your script and "return" if found. You will need to remove that token when they get healed.
Just a minor tip to improve processing: testing for a single condition (like "<") is faster than for a combination of conditions like "<=". Change your "<=0" tests into "<1", or whatever level of precision is the equivalent for the variable type.