Leadership skills

Good day Today I went to Pick n pay Clothing in Harbour bay Mall and as the cashier was assisting me ,the manager/ person in charge came to the front and loudly said "are you resigning because of management " and the cashier was hesitant to respond because I was standing right there ,and then she responded I found a better opportunity. Why did the manager put the poor lady on the spot like that infront of customers and then just walk away. If she had to discuss something with the cashier she was supposed to take her to the office and speak in private to her . I always get great service from staff working there but since this lady started working there ,I can even feel the atmosphere in the shop is different not so welcoming anymore ,its the way the manager is towards the staff and she must lead not intimidate the staff .