My wife had a similar thing happen (not a TN visa though). The immigration lawyers got to work and she was allowed to try again a couple weeks later. This time the officer agreed with the assessment that she was qualified for that visa type. The original officer had a very narrow perspective on how a certain job title was defined that was not inline with how most companies operate.
If your company has a Canadian office, the lawyers could try getting you on an L visa. Or there's an E visa. Once you're on one of those visas then your company can sponsor a green card. Green cards are much more stable and they're easier to renew. Then citizenship if you want to go that far.