That’s all I can find. Interesting to see it discussed without much fuss.
I can see both sides to this, TBH.
If he means what he just saw I agree with @TTF’s view that it shows he’s so dozy he missed it.
OTOH no one ever said goodbye to a shoe so Homer saying that is automatically funny because obviously no one should have ever witnessed it.
I have to go with @ericVI though.