The Spigel article says that Americans helped flee Barbie to Bolivia in 1951. In some Polish source I found that in 1951 he fleed to Argentina, with the help of catholic bishop Alois Hudal (the one who helped dr Mengele), and then Barbie fleed to Bolivia.
if you add anything like that to Wikifedia, they'll just reverse it and threaten to ban your account for not using Trustworthy Sources(TM) like the CIA World Factbook