Numbers are important to understanding the world, though of course there could be bias in any data set. It would be really worthwhile if you could identify a potential cause for bias in the data set. When data seems strange, it could be a sampling artifact (bias), or it could be real and up to us to uncover the reason for the strangeness...
I'll put my tin-foil speculations hat on for a second to offer a pro gun explanation for the data: what if higher rates of gun ownership led overall to fewer crimes overall because some sort of deterrence from gun owning population?
The point is, it could be bias, however the differences are quite large, suggesting that it's more likely to be incomplete understanding of the factors at play, warranting research studies to investigate why such differences in crime might exist between two quite similar countries.