Has an Olympic Baseball game ever ended 19-1?
Exactly once. On August 3, 1984, Japan beat Nicaragua 19-1, and no Olympic Baseball game before or since has ended that way. When it happened it was a scorigami, the first 19-1 in league history.
That makes 19-1 the 48th most common final score out of 87 that have ever occurred in Olympic Baseball. One point away, 20-1 has happened never and 19-2 has happened never.