Allowing Anglican ministers to concelebrate a liturgical service at an altar of the pope’s cathedral was a cause of scandal for Catholics that should never have happened, according to a prominent canonist, even if it was a well-intentioned act of ecumenical generosity.The controversy erupted after a group of 50 Anglican ministers from the Fulham area of London led by their bishop, Anglican Bishop Jonathan Baker, concelebrated a liturgy at the altar in the Archbasilica of St. John Lateran on April 18.