I know there is someone on Xmarks who is associated with the Stormont, Dundas and Glengarry Highlanders who are from the Morrisville area, and so have all confidence that this will get sorted by someone more knowledgable than I, but the sporran of the officer in question looks like the SDG Highlanders, not Camerons. A news report of the event (the commemoration of the Battle for Chrysler's Farm) also notes that Mr Harper also announced that the regiment has received news that HM the Queen has agreed to become their Colonel-in-Chief.

The tartan then would be Macdonell of Glengarry