Minion Pact support - Cannot be triggered

https://www.youtube.com/watch?v=gUbhCmW8bWk

Minion Pact Support does not work with Cast When Damage Taken Support.

As you can see in the video, Fireball is triggered as expected, however no minion is consumed. There is no reference in the gem to Minion Pact not working with Trigger skills. This is a bug