This One Time at Space Camp... - S4-E18
Plot hole: When Dr. Hughes is racing to save Allison when he thinks he is Carter from the events that happened in "I'll Be Seeing You" Henry says he is racing for a cliff, and that the cabin was just a hologram. But in the episode the Cliff was the hologram disguising the cabin. Henry even commented in that episode that he did not remember a cliff being there.
This One Time at Space Camp... - S4-E18
Other mistake: When Holly and Fargo are playing Dungeons and Dragons, Holly rolls a d20 die and yells, "Critical hit!" but we can see the 20 on one of the upper sides of the die, meaning that she actually rolled a 2, which is most definitely not a critical hit (and actually nearly a critical miss).
Chosen answer: He's still around, we've just not seen him lately, as scenes with Blake have been mainly at work, where Kevin wouldn't be.
Tailkinker ★