what gets missed so often in talks about online radicalization--eg youtube recommendations--is that the people getting radicalized already had pre existing reactionary inclinations and inhibitions which pulled them into making their first step down the rabbit hole and lubricated the pipeline thereafter
what the radicalization process did was give self awareness, ideological coherence, social connection, and concrete political form to their libidinal turbulence of unprocessed emotions and unconscious desires
by contrast many other people unsuspectingly encountered the same propaganda and were immediately repulsed and had an instinctive suspicion of what was really going on
ie radicalization is more of a search, selection, developmental, and evolutionary process of pliable potential candidates than one of indoctrination or 'brainwashing' or otherwise normal people
so yes that person was always a fascist at some level but they did not know it at the time and their experience with cryptofascist memes helped them realize who they were politically and where their allegiances lie
so 'radicalization' is basically the rightwing version of gaining class consciousness (via binge watching hate bait and lurking) but for the white settler petite bourgeoisie