"It's the same thing," he insists fiercely. His world had that much reality; it had to have done, or there was no point to anything. "If I didn't do it here, I did it somewhere."

The other part is a little more tempting. But he can't really buy it, after a moment. "If it didn't happen, why'd it just happen?" He has, pretty incontrovertably, turned into Oswald. It didn't last, but who's to say it won't sometime? What is he going to do next November, or on the anniversary of Oswald's birth, or literally any other important time?

(The man's deathday has come and gone already with no change. That's some comfort.)