That wouldn't have been Harry Townes (Reger), but Lev Mailer aka Ralph Maurer (Bilar), the bowler-hatted fellow who first greeted the landing party on their arrival.
What was up, though, with the high pitched looping for Harry Townes during the exterior scenes when he leads the landing party to safety? "They're in the body, it's Landru." Yet, in the middle of that we get a close up where he says "It's too late. Look" and his voice is normal. Was the high pitch Townes' voice but screwed up in the studio, or another voice actor trying to imitate him (and failing miserably)?
It could be the actor himself having to loop a line and just not doing it the same as when the scene was filmed.
(Oh, and 'Looping' is having an actor come in to re-do a line and having the sound editor re-insert it because audio gotten during the actual take was not good enough - and there can be a lot of reasons why that happened.)