Couple of comments:

1. I would argue that the first outfit to blame is the third party medical advisor.

2. On a DEL-YUL flight, at the time when the emergency started, which locations would have been available for a diversion, how much support available, and how long to get there?

3. The trade off is the risk for one individual vs. the inconvenience for the other passengers. Assessing the risk is subjected to significant uncertainty.

Bottom line: I don't see that it's so easy to reach a conclusion either way. Not enough information. But surely AC can redirect at least some of the blame to the medical advisor.