Misandry
It would seem that the researchers are suffering from confirmation bias: Only men are the perpetrators of sexism and only women are the victims. As that is an assumption based on gender; it is, by definition, sexist.
When are they going to publish research about the sexist attitudes of women? Or research of sexist attitudes towards men?
P.S. before you down-vote, how many of you knew of the word "misandry" before you googled it? My spell checker does not recognise the word, but it has no problem with misogyny.