iCalcreator knows that certain iCal properties (e.g. ATTENDEE) can have
multiple entries in a single VEVENT. So when you access ATTENDEE for the
first time, it gives you the first entry. Accessing it a second time gives
back the second entry, or at least it tries to. If there is no second
entry, iCalcreator returns False.

Since Date iCal does not yet support multi-entry properties, I had to work
around this functionality to ensure that hooks which add custom mappings
don't run afoul of this process.