 00-00-0000, 00:00 PM Well after a double tap to the head does nothing but knock him out its fairly obvious something is wrong. From there McClain could run the gamut of damage types trying to find something that would work. Assuming McClain does get the first shot and does shoot Dunn in the head, knocking him out, McClain would assume Dunn was dead. I certainly can't see him deducing that Dunn is bulletproof fast enough to restrain what should be by all rights a cadaver and mount some kind of grotesque, unMcClainesque series of test. 