A hotfix was applied to The Division today during another downtime, and players should notice better stability.
The Division: hotfix kills Competent glitch, should resolve server instability
Players will now notice they can no longer revive others twice by holding the Revive key.
The team also fixed a bug where Talent effects could be stacked by repeatedly switching the equipped weapon.
The latter should also resolve recent server instability which the developer said was "due to the increased traffic generated by this bug." Hopefully, this means the lag issue has been fixed.
Sounds like the Competent glitch and the others were indeed slowing everything down as presumed.