I actually had a similar thing happen to me. I was in seat 1 and was all in preflop against seat2. Back then, in this room you had to turn your cards face up even in a cash game. So we both turn over our cards ( my KK his AA)
the dealer looks and grabs my cards and starts to place them in the muck. I instinctively grab his wrist to stop him from mucking my cards. He says "never touch a dealer!" And I say I normally wouldnt but I had to stop you from mucking my cards. You havent put out the flop yet.
He says "I dont care, you cant touch a dealer". I said call the floor if you are that upset about it. The floor came, and the first words out of his mouth were "did your cards hit the muck?" And I said no, because I grabbed his wrist to stop him. The floor says "you cant touch a dealer" and then "you have to protect your hand". I said that's what I was doing by grabbing his wrist.
Then the floor says "well your hand isnt necessarily dead if they hit the muck". And I answered "then why was that the very first thing you asked about if it didnt matter". I could see we were stuck in a loop of " you must protect your hand--i protected it by stopping him from mucking--but you cant touch the dealer---etc.
So eventually he just had the dealer run out the board, and as much as I would like to say I sucked out, I didnt. But until I read this OP I thought my incident was the only time a dealer had forgotten to put out a flop. I guess no matter how strange something is, it's happened before.