He said "biologically immortal." However, the definition of agelessness is in fact the condition of not being able to determine one's age, or one's body never aging. True, "ageless" does not mean the same thing as "immortal." The problem is that agelessness is closely/commonly associated with immortality.
You may want to clarity just for some folks, the distinction.
Edit: I've gotta agree though, you should probably do a quick sub for safety's sake.