A. Gibbons made a perfectly sensible move. You can argue it the other way but it was hardly an eggregious decision.
B. Pillar had no reason to be surprised much less upset that Gibbons would follow the platoon advantage since that's exactly how Pillar has been used thus far. He has no business questionning his manager, generally speaking, but this was especially odd and incredibly short-sighted on his part. That he did his little display in a relatively calm fashion if anything just makes it more strange. It doesn't make him look passionate, it just makes him look very dumb and/or very conceited.