Decrypting isn't an all or nothing. For radios with slaved encryption TX, they cannot "toggle off" encryption. For radios being decrypted in waves, it is as simple as the TX being slaved to unencrypted, but the encryption keys being left in the radios. Any radio transmitting in the clear but remaining programmed with the encryption keys would operate the same as a radio with encryption toggled off, and that would be it would TX in the CLEAR and RX all clear and encrypted comms. There would be no difference in operation for the personnel involved, and unless they looked at the radio display to see if the cross hatch 0 was present, they would have no way to even know their radio had been changed to TX clear.,
Paul