Reliability of a compression barb fitting for a water hose
Answering own question: I disassembled the connection with the purpose of removing possible traces of leftover silicone oil from it. When I removed the compression nut and pulled the tube off the barb, I noticed that the end of the tube has become noticeably flared, because the compression nut, well, compressed it and pulled somewhat forward on the barb. Since the tubing is on the hard side, I am sure this natural flaring alone is more than adequate to prevent the tube from coming off the barb through the retaining nuts, despite some hydraulic hammering from faucet operation and jiggling of the tubing caused by it.

I wanted to post a picture, but the transparent tubing material did not allow for a good snapshot.