It wasn't the nationalist version, any state flag is inherently a nationalist symbol, the problem is that the logo is from the NDH, a Nazi puppet state of Croatia, which created the Jasenovac concentration camp.
It might be a mistake, but as a young adult, everyone around me (I live in Croatia) knows what the 'first white square' symbolizes.
More likely, a deliberate choice made by a powerful individual, for which anyone with any actual knowledge or proof knows all to well that it would be suicide to talk about it publicly. Whether that would be literal or figurative suicide, that is debatable. Either way though, while Croatia is part of the EU these days, the way in which things function are still very much similar to some other countries in the region .. where powerful individuals can make arbitrary decisions with absolute impunity.
There are plenty of powerful individuals in Croatia who harbor strong sympathies towards the country's dark fascist history. Plenty of those managed to get away with their role in war profiteering (or worse), during the last wars. Probably more than anything because they happened to be useful and on the side of powerful corrupt people in the USA and EU. Regretfully so, because Croatia is beautiful country and home to some incredibly whole/goodhearted people (very much like in other former Yugoslavian states).
To clarify, I mean the printer as a company, not the device .. and yes, it indeed is as bad as blaming the intern.