Severe gum pain following root canal procedure that was less than what I would call routine.

Not routine ... . But few questions I have can get the answer u want ... 1) is the root canal done by endodontist/specialist? Because they, might have used "rubber dam " where sometimes the clamping is slipped on to the gum line causing pain aferwards.. And its transient. 2) did u have any fistula/abscess/history of periodontal problem prior to the root canal. Since that can also contribute to the issue.