When there is a remote chance of a big payoff. Simple
My first job was in a grocery store many decades ago, and I saw all manner of attempted hoax “accidents” in order to cash in - and they were almost ALWAYS perpetrated by black women. We’d watch them in the produce section throw grapes on the floor and then try to “slip” on them.
This was in the days before ubiquitous surveillance cameras, so we had to be very vigilant.