When the Little Woman is putting Harry into the guillotine, the same character can be seen in the background when the camera angle changes.
When Fear is shown the shot before Harry is put into the guillotine he is shown away from the guillotine (and away from most of the other character), but when shown when Harry is in the guillotine he is in front of the huddled group behind him looking directly at Harry's head.
When the top of the guillotine is lowered over the neck of the one alien, it shows that there is no slit in the top for the blade to fall through.
When the Clown tortures Harry by making him old, all stand towards the center of the yellow and red pinwheel painted floor, then the Clown turns Harry into a baby and tosses him in the air a few times. When doing this, a purple mat appears below them on the floor, then the Clown changes Harry back and the mat disappears.
As a Vulcan, Mr. Tuvok would presumably not be susceptible to the psychological effects of fear and could have intervened in the environment of the simulation. A similar situation arose in Spectre of the Gun (1968), in which the Enterprise NCC-1701 crew were forced into a recreation of the gunfight at the OK Corral in Arizona in 1881. Recognizing that these images were entirely fictitious and therefore could do him no harm, Mr. Spock had no fear, and the gunfighters could do him no harm.
Later it's established that Voyager can send the Doctor into the holographic environment without risk. Since they don't know what to expect when they first found the pods it seems they should've sent the Doctor in first to verify that it is indeed safe for a biological person to enter the environment. Instead of sending Harry and B'Elanna.
According to the Prime Directive which Voyager's crew supposedly follows, they have no business interfering with the sleeping Kohl, so the entire plot should never have happened.