The gemara cites two pesukim. Rak hishomer and venishmartem me'od. The first is unconnected to personal safety and the second entirely connected. Why does the gemara need the first.
Andrew Scher, London, UK
The Maharsha comments that the first verse is talking about not forgetting one's learning, and the second about not believing in images.
In fact, neither verse is talking about life preservation. That being the case, the officer expounded both Pesukim out of context. Chazal themselves often do this. Indeed, the Gemara in Shevuos derives from the first verse that one should not curse oneself, as the Maharsha points out.