Try reading Alitair Hornes book, 'How to lose a battle' about the German invasion of France. Very interesting and shows that the French effectively defeated themselves in the years preceeding the invasion with poor planning, a number of totally useless Governments and internal dissent. Yes they fought well at Verdun, but that is where the seeds of loss were first sown for 1940.
Considering the French 'Counter-attacks' that had already happened, the incompetence of their high-command and the defeatist attitude already in place at all levels of the army then Gort was probably right to pull back to the channel and scarper.