Know the rule to break it

A while back had this line of dialogue come my way:

“We can do this the easy way or the hard way, up to you.”

The line bothered me because changing this comma to a period is techincally correct, but there is an argument to leave it as a comma splice. But It also could be an em-dash, semicolon or period, depending on emphasis.

As my editor said, "It’s one’a them know-the-rule-to-break-it deals."