Your question is about the difference between “abstaining” and “recusing oneself”.
When people recuse themselves, they leave the room. If they aren't there, they can't influence the discussion. Other people are free to make comments without offending anyone or say that there's something inappropriate about the relationship between the chair and the company. For that reason, recusal allows the board to make a decision on the matter.
If someone says they are in a conflict of interest and simply abstains from voting, they remain in the room. However, their presence alone can influence the decision or affect the free flow of discussion. For that reason, the act requires that people recuse themselves.
For some reason that's unclear to me, Ms. Verschuren didn't do that. Sustainable Development Technology Canada allowed her to abstain from voting, but didn't insist that she recuse herself. The board held a general vote on resolutions as a whole, to settle everything, and that included Ms. Verschuren's companies. She voted for that. That's not possible: Someone can't say they are abstaining from voting on a specific thing due to a conflict of interest, and then vote on the resolutions as a whole, including the company presenting the conflict of interest. That was a technical breach of the act. I don't know, it may be the result of ignorance on some level or a lack of information, but the act is very clear: Ms. Verschuren was required to leave the room, but she didn't.