Sean basically said it. If you are in a noisy RF environment, then the signals that do "leak" through would cause problems in the decoder. It would freeze operation for a second or so and then unlock if good information comes in. If the interference persists, then the receiver would stay in lockout or move the servos to your pre-programmed failsafe positions.

You'll have to try the system in an area that doesn't have so much RFI.

PCM is not interference proof.