Sure he did. Maybe in your imagination. And since we're on the subject - why don't you post the legal company name, physical company address and website if any?
You say Sam is a good and kindly fellow, and worked hard all day, but did he ever get even one shingle installed? By your description of Sam we have to have pity on him, and wonder if possibly he could be a little bit "slow". Hopefully you didn't take advantage of him, and paid him, for at least the time he was at your residence!
When this roofing company comes to your residence you will notice their arrival by a bicycle towing a child's wagon, loaded with a small bundle of used shingles, a can of straightened out roofing nails, and a kitchen step-stool.