Interesting you bring this up. A good firend of mine is a dentist and he was telling me just yesterday that days ago, they had a By-Law Officer show up. They have their door locked so people can't randomy come and go. There was a knock at the door and when his receptionist went to the door to check because they weren't expecting anyone, there he was. Apparently he asked to come in, took a look around, wished them all a nice day and left. Obviously looking for people not wearing masks, social distancing, etc. The receptionist said when he left, he went to a florist shop, a few doors down. My buddy was thinking that maybe someone reported them. Even though they are following protocols maybe a disgruntled patient.
Reading you post maybe it was just a random check.
I'm very much against unwarranted search or questioning by law enforcement but in these times, I am glad to hear that they are checking and enforcing the rules.