It has everything to do with natures, EVs and IVs. What sumwun is saying is that Eviolite doesn't apply to the base stat as you've suggested, it applies to the Pokemon's actual, fully calculated stat (which considers all those things in its calculation). So it's not exactly 45 * 1.5, but rather [Krokorok's stat] * 1.5. Again that stat is not the base stat, it's the full stat like you see on the Pokemon's summary page. Eviolite would be much less helpful if it only affected base stats.
Keep your chill mate, he's only trying to help.