lemon said that people approving Bercow's ruling are Remainers and so are biased.
The implication being that Leavers, who are such rational, unbiased and well judging folks (with a thorough knowledge of parliamentary procedure honed by years of study) are absolutely right to be screaming 'traitor' at him.
Maryeliza did indeed have it correct that cuts both ways.
Of course, Bercow knows absolutely nothing about Parliamentary procedure. He's only the Speaker of the House of Commons. 
How to Keep Living at Home Longer
