The situation: Somebody important is being filmed live, and/or giving a speech in front of a crowd of hundreds of thousands of people.
A highly unlikely, but within the realm of possibility, physical anomaly like spontaneous human combustion, or quantum tunneling a minuscule but visible distance, occurs to said person.
During what OTL speech or event could this have the biggest effect?
This may seem ASB, but the whole point is that it's theoretically possible. And it's only one highly unlikely event, not a whole series of them.