No.
In this case, the kid was nothing but deliberate in his plans to destroy a culture in part, in actions that we know he knew had directly caused mass fatality genocidal incidents in the past. He thought it was justified, to spread his religion, but that doesn’t make it less a risk of a genocidal incident.
You said a remote tribe could easily handle a cold, because “they have to deal with a lot more bacteria and parasites than the average person does today.”
That’s not how colds work. Don’t double-down on dangerous and useless medical advice. Any infectious disease can be lethal to remote tribes.
