Michel Dupont, of the FTQ; Michel Angers, of the CSN; Yves St-Pierre, of Action-Chmage; Jean-Louis Lavoie, of the Mauricie St-Jean-Baptiste society; Franois Brunette, of the AQDR; Martin Roy, of the UQTR students' association; and Brian Barton, of the Trois-Rivires Solidarit populaire.
Mauricie St-Jean is from the Baptiste society
The full society name is Mauricie St-Jean-Baptiste, so to say someone called Mauricie St-Jean is from the Baptiste society is therefore incorrect. The system likely got confused  with the difficult list of names, particularly because they include hyphens.
( z1 be-from :ARG1 ( z2 person :name ( z3 name :op "Mauricie" :op "St-Jean" ) ) :ARG2 ( z4 society :name ( z5 name :op "Baptiste" ) ) )