VW Group of America CEO calls on company ‘to bloody learn’ after Martin Winterkorn’s exit in the wake of emissions scandalLike many chief executives, Martin Winterkorn was a demanding boss who didn’t like failure. But critics say the pressure on managers at Volkswagen was unusual, which may go some way to explaining the crisis at the carmaker.Three weeks after it admitted to cheating US emissions tests, Europe’s largest carmaker is under pressure to identify who exactly was responsible.