Paly students do ride their bikes the wrong way down Churchill but not excusing them, it is quite apparent why they do it. They are riding along the left side of the driveway on campus, turn left onto a wide bike/pedestrian path designed to meet up with the path beside Caltrain tracks. Then they continue onwards to cross Alma and stay on the left because it is almost impossible at that stage to cross to the right.
Crossing at the exit to Paly and then staying in a bike lane that is in the middle of two lanes of traffic seems pretty dangerous, particularly for the large number of bikes that are there after school. There just isn't enough space for the bikes to wait for the light to change, particularly if there is a train coming and the gates come down.
I am not sure of a solution, but something needs to be done to address this