Ghana Immigration is going through a lot of training in passenger profiling and I believe what BL went through was exactly that - The white woman was the trainer and the 2 black ladies behind her were being trained.
Part of their training includes how to scrutinize passports, profiling the passenger to determine if they are a terrorist, sex tourist, drug mule, etc..
I guess this is why I was shocked as I'm a resident here and no one bothers me at the airport as I know a lot of the people there so am always greeting the workers there when I travel.
GC