drivers side wiper

[Ramiro0727]

Hello,

This morning while driving to work and it was raining. I had my wipers on and the drivers side wiper came off. I pulled over and retrieved the wiper arm. When i got to work I noticed the spline cap that goes on the wiper linkage was still inside the bottom of the wiper arm. Does the spline cap supposed to stay on the wiper linkage? Or does it easily come off. Attached is a picture of what im talking about.

Thanks,
Ramiro