Here you're confusing war time operations, where for example you may only get one hit on a target due to him being distant or whatever, and deliberate killing i

Here you're confusing war time operations, where for example you may only get one hit on a target due to him being distant or whatever, and deliberate killing is most certainly allowed, vs. what is ostensibly a peace time police style operation. In the latter, an order to kill the targets no matter what is likely to be illegal (but in a case like this arguably a matter of foreign policy). What ammo is used it likely to be a lot less important than how it's employed. For example, per one account a number of them were hosed down with machine guns, and the only hollow point ammo used, or plausibly used (since it doesn't tend to work well in semi-auto or full auto weapons unless they were designed or modified for it) was in .357 revolvers used by the close combat team. And strangely enough, 3 survived.... As for the Hague convention, I haven't studied it and its genesis in any detail, but the general idea was to make war less barbaric. Whatever is later said to troops who for political reasons are required to use much less effective ammo that's much more likely to get them killed is at minimum suspect. E.g. logically taking someone you shoot out of the war altogether, by killing or maiming them, is vastly superior to their coming back after convalescence.