It's all possible, of course, and also has plausibility in that it happened ex-US so would be hard to track down. It also contains a couple of other well-known sayings:
1) A Smith and Wesson beats 4 aces
2) A Smith and Wesson also beats 3 <---->
3) The sound of racking a single-shot 16 ga shotgun will not necessarily send anyone running.