Once in EMERGENCY state, only legal option should be reset.

If you look at the state transition diagram in the rules, you'll see that the AS_EMERGENCY state (which is the state we enter after requesting EBS) is only allowed to transition to AS_OFF.

Currently, this is not the case. After you request EBS, you will be able to enter the manual driving state simply by clicking on the drive_manually button. If you instead select an autonomous mission, it will try to launch the mission.

This should be changed such that once in the AS_EMERGENCY state, the only legal option is to reset the state machine (i.e transition to AS_OFF).