In response to: “Did he do anything illegal? “
Under existing law (and yes, they had public international law at the time) it was widely debated whether the Europeans had the “right” to go into America and conquering people and stealing their land (as well as going into Africa to kidnap people for slaves). In general the lawyers said “NO”, most governments instructed their agents to behaive themselves, and the people “on the ground” in America decided that there weren’t any lawyers for thousands of miles and most governments would not be too upset when the cash rolled in.
The Bnei Yisrael conquered Canaan only because Ha-Shem told them to. The Europeans never claimed that had a divine mandate to engage in slavery or conquest (the closest is the American idea of “manifest destiny”, and not really). Unless Ha-Shem tells you to do so, theft and murder are not allowed, even for goyim.