This I believe is what Gowling will assert to obtain a higher percentage - all my opinion of course and NOT legal advice.
1. The monitor suggested offering shareholders an opportunity to participate in the 4th DIP. The company failed to do this and this seems a possible oppression argument and imho the best chance for improving the shareholder share. I can't remember how much was lost in the 4th DIP but a change to this is significant (but not the pie-in-the-sky $2 range - shame on you!).
2. A breach of section 347 of the criminal code. This is a scare tactic by Gowling - close-to-zero chance of success, intended to encourage Tenor to give up something. It won't work and they know it.
3. There is also some technicality about the NAP transfer agreement but as this document is redacted for us there is not much to say. I think it is there just because it's a lawyer's rule of thumb to have 3 reasons.
If you want to assess the chance for yourself read the monitor report prior to the 4th DIP and see if you feel / felt oppressed. Not that your feelings matter legally but it will give you something to hang your indignation on. Legally, the way the company has betrayed shareholders will weigh on the court and coupled with the windfall Tenor may get is reason to give opt ins hope (but remember it will only affect the 4th DIP).