It seems that all ics attachments sent from the F2F module create the .ics with a method of "CANCEL." Hence, Gmail and most likely other applications show all ILT events as cancelled. Here is the top part of the source from one of the ILT event attachments (note that this was a future event that had NOT been cancelled in anyway via the UX):
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Moodle//NONSGML Facetoface//EN
METHOD:CANCEL
BEGIN:VEVENT