Revealing mistake: When the dad inserts the rectal thermometer into Calvin and he looks up, the CGI head is too obvious, especially when he is putting his head back down on the bed.
Revealing mistake: Numerous times throughout the film the CGI used to show Calvin's height is very obvious. An early example is when he climbs on Percy's back to look in the window.
Answer: He isn't seen but given the ruckus going on at the time it's highly probable he just stepped out of the way and is hidden in among the crowd.
Ssiscool ★