You don't get it. Why should I care sufficiently about your
parochial "event" even to question or seek its "truth" ? Has anybody other than a baseball follower ever had cause to question "its certainty", and even amongst them
I'm willing to bet that the word "certainty" about it, has hardly if ever arisen. Its assertion or denial is meaningless to me.
If you want to play philosophical games about "context free "certainty" " I suggest that you simply end up down an absolutist
backwater familiar to religionists. There are simply too many potential candidates for "event-hood" to say anything useful about "certainty" other than to note the social functionality of that word in cases of doubt.