Ryan's childlike glee at successfully dumping a cup of blobs on Shane's head immediately followed by the very real childlike fear of Shane getting back at him, which was so strong that he literally ran out of frame giggling
For those who are behind and are alarmed: Shane and Ryan "splitting up" is a bit in Mystery Files (specifically the debriefs) where they stopped being friends after Ryan says he doesn't pay attention during Shane's presentations. It's similar to the Steven vs Ricky bits in Too Many Spirits, or Shane not caring that Ryan was about to be skinned alive in Puppet History. The Ghoul Boys and Watcher aren't going anywhere. It's just a bit. You can breathe. :)
Ryan jump scaring the audience at the Ghost Files show by sprinting on stage because the crew backstage was annoyed by the bar on the viewing screen is peak theatre