As written it sounds like one is to reserve the mixture with eggs. I have never seen a glaze with eggs and wanted to clarify. Seems like it would be the cabernet, cocoa, butter and sugar.
That's how we tested it, after having added the eggs! It's an unusual step, but we didn't have any problems with it.
You bring up a great point. This is actually how we made the cake and it turned out beautifully. The glaze is poured over the still-hot cake -- still, you should only make this with eggs you trust.