Big guy and impressive arm. That tape was not pulled tight and on a straight angle. Also there is a question about a plastic or cloth tape being used. Plastic is not always true. Cloth tends to shrink or expand with use. Need to check them against a true metal yard stick.
A true measurement should be taken with a thin steel tape and first thing in the morning. When the feet hit the floor, take the measurement. Before brushing the teeth, pinching off a loaf, or whatever. First measurement, when the arm is hanging free at the side (unflexed). Second in the usual bicep/tricep flex. Compare the ratio between each.
I would rather take the measurement of that blond any time. And by all means, last thing at night and first thing in the morning. Also Flex did a good job on the interview...still has the guns. And his health...I guess.