Lost all control of robot, incl'd E-Stop

[isaacdl]

Yesterday we had an interesting and rather disturbing incident with the robot. I was driving it around in teleop, everything working perfectly. I had full control of the robot. I put it into a slow rotation (we have mecanum drive), and all of a sudden I lost control. It continued in that slow rotation, without any input from the joysticks. I assumed it was a problem with the gyroscope feedback loop that we're using to correct rotational drift and immediately hit the disable button. The driver station said it was disabled ("Teleoperated Disabled"), but the robot was still moving. So I hit the E-stop, and the driver station said that the robot was E-stopped, but the robot was still moving. Luckily it was moving fairly slowly and we could hit the main breaker, but it still makes me nervous. What if I'd been going straight at full speed...

When we turned the robot back on, everything was working just fine, with full control of the robot.

Any ideas why this happened?