Berry Confusing

I go into a chain smoothie store with a friend. It’s late in the hot summery day, so the employee says:

Employee: “Just to let you know, we’re out of all the berry flavors.”

Me: “Oh, that sucks. Well, this coupon has to be used today, so I guess I’ll get something.”

I check the menu.

Me: “Do you have peanut butter?”

Employee: “Yeah!”

Me: “I’ll take that then. It’s a shame, I was really looking forward to having the acai.”

Employee: “Oh, we have that!”

Me: “You do?”

Employee: “Yeah! Would you like an acai smoothie?”

Me: “Uh, yes! I thought you said you were out of all the berry flavors?”

Employee: “Yeah, but acai isn’t a berry; otherwise, it would be called a berry.”

Me: “It might not be in the name like strawberry, but it’s a berry.”

Employee: “Look, do you want your acai smoothie or not?”

Me: “I’ll take it?”

Friend: “Technically, strawberries aren’t berries.”

Me: “Not, now, [Friend]!”