I met Frank years ago and have purchased amplifiers from him. When I lived in Minnesota, I visited his shop in Burnsville, a Minneapolis suburb. He builds excellent equipment but, in my limited but direct experience with him, he can come off as crusty, highly opinionated and an acquired taste.
OPs problem though seems different. He needed communication but did not get it. Small outfit so it is not hard to see how something like this can fall between the cracks. I guess I would place more emphasis on how he responded to his shortcoming being pointed out to him than to the screw up of the initial mistake.