You say this employee has been "jerky" to your dad. I will take yours and his word. But, having worked in a bank that last sentence you posted could be interpreted as your dad being "jerky" to the bankers as well. Two different sides of the counter I guess and both could be interpreting things differently.
Previous poster is also right about safety, especially for the elderly. You would be surprised how many times elderly people fall for scams and want huge amounts of cash withdrawn to get their grandson out of jail, fix their roof, or pay off something. A good bank will look out for it's clientel.