Outlook 2011 for Mac "could not synchronize record"error
It turns out that these meetings were still on the hard drive. I went to Finder, searched on the title of the meetings (which was in the Error message itself), and simply deleted the files in question. They were kind of "grayed out", which led me to believe they were either owned by another user or had failed to get deleted correctly.
Seems like I have resolved the issue, by right clicking on the folder that was having issues (my Drafts folder), selecting "Properties" and under "General" clicking "Empty Cache"