Microwaves are not nuclear! Microwaves agatate water molecules. Have you ever put a empty glass in a microwave??? It will not get hot it NEEDS water.
The shop pics are mine, and the holes are stuffed with wet rags after the wood is put in it, and it contains the waves.
As to the hole burned through the wood....I would have to see that to believe it......I have NEVER seen anything remotely close happen to what you describe.
Take a piece of paper "dry" stick it in the microwave for 2 minutes NOTHING WILL HAPPEN the paper being dry will not conduct heat because of a lack of water. If there is any grease it will heat up, and THAT may start it to burn......but otherwise nothing!
Brian