Yes, if what usually happens in private (and what you are hoping to demonstrate to another person or an audience) is different from what happens when you demonstrate it, you can [0] call it Vorführeffekt.

[0] since it's not an actual effect [0a], kinda like Murphy's law isn't a real law, you can call it that way, but you're not required to.

[0a] other than maybe nervousness of the presenter affecting things, but I don't think Windows is ever nervous about crashing.