In my comments on car salesmen above, I never use terms like "must" or "fire". But since you brought it up, if I were the manager and the interviewee is driving another brand, I would at least ask what is his/her intention regarding that car if he/she were hired as one of my permanent staff. If there were another applicant, who is *equally qualified* but drives my company's brand, wouldn't you hire that person first?
I am very curious to hear what you would do in this particular case. You were the Apple Store manager, and you saw your salesperson pulled out a Samsung S7 on the sales floor, either for his/her personal use, or even worse, showing it to a customer. What would you tell him or her?
I am indeed in management, and perhaps for that reason, I naturally think and act in a company's interest. I can see that those think from the employees' point of view would find my comments unreasonable.