The person in question also seems to shout "I love Venice" at 0:52, which is another indication of that person being Dennis.
Dunno about that one, but it is definitely DW saying "I love Shawn" - just before the camera cuts away, he leans into the mic and the "I" fits the video.
Odd... I met Dennis a few months later, in October '81, and his voice was much raspier then.