When Craig is interviewing Sir Frederick in his office near the start of the episode, a picture is seen on the wall featuring a statue of a man on a plinth in a wooden frame. Later on, in the Surgeon's office, the same picture in the same frame can be seen on the wall.
Craig is in a room which is suddenly filled with gas, which proceeds to knock him out. Later, he dives off a dock and holds his breath underwater, longer than the average person would be able to. Why didn't he do this in the room with the gas? He would have instinctively known to try to hold his breath, so wouldn't it have worked the same as it did underwater?
When Mr. Hallam, the surgeon, is checking Sir Frederick for life signs he places the stethoscope over his stomach rather than over the heart which would give both heart or lung sounds.