...alright nevermind, I figured it out. For those looking for the solution on line 215 of jcomments-v2.1.js.
init() tries to restore fields from a previous session (?)
init: function(id,editor){var f=this;this.id=id;this.form=this.$(id);this.editor=editor;this.events=new JCommentsEvents();this.setElements(new Array('name','email','homepage','title','comment'));this.restoreValues();this.clear('captcha');this.setCaptcha();},
So, I simply removed setElements() and restoreValues()
init: function(id,editor){var f=this;this.id=id;this.form=this.$(id);this.editor=editor;this.events=new JCommentsEvents();this.clear('captcha');this.setCaptcha();},
Seems to do the trick and the form still validates and submits just fine.