Full Idea
Events are relatively coarse-grained, unlike facts; so the event of John's saying 'hello' seems to be the same event as John's saying 'hello' loudly, while they seem to be different facts.
Gist of Idea
Events are fairly course-grained (just saying 'hello'), unlike facts (like saying 'hello' loudly)
Source
Jonathan Schaffer (The Metaphysics of Causation [2007], 1)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.2
A Reaction
The example seems good support for facts, since saying 'hello' loudly could have quite different effects from just saying 'hello'. I also incline temperamentally towards a fine-grained account, because it is more reductivist.