A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
>> Apparently the font they were all using was an option for my user in Powerpoint, but it was not actually installed on their system.
It's a bug in PowerPoint. It shows you the fonts used in the presentation in the font dropdown, whether they're actually available/installed or not.
Easiest quickie test to see if this is the teeth that are biting you: Start a new presentation based on one of Microsoft's templates/thems, add some text and check to see if the questionable font is on the fonts dropdown. If not, it's not installed and you have your answer.