He probably knows Glenda’s gone. When it gets colder than a witches t-t in those rockies witches tend to fly to a more moderate climate. She didn’t cast a spell on you, did she??
I thought Glenda went to Hawaii for winter. Maybe she was coming back and got tired and looked for the nearest witch landing pad. By some coincidence, Tubebender must have a witch landing pad next to his compost pile.