The Falcon 50 only has a single thrust reverser, and it is fitted to the centerline engine.  The nacelles on each side are not fitted with reversers.  I was quite a way down the runway from this Falcon when it landed, and I could hear the reverser kick in.  I was not expecting it to stay in reverse for very long, but they kept it in all the way through the roll out and even as they exited to the taxiway.  Is that normal procedure?