It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

I finished the Tenderizer/Shell game mission, but the recommendations at the end said something to the effect of "Knowing why the Shivan fighters showed up would be useful in predicting future Shivan attacks. Try doing things differently".
Has anyone found out a solution to this? I tried replaying the mission and scanning every object, but I didn't find anything that could have alerted them.
P.S. I'm posting this as a separate topic as my other post was originally about a bug.
Apparently destroying one of the Azrael transports is what triggers the fighters (hardlight wiki).
Thanks for the answer and the link.
Gah I give up.
I did exactly as they said. I took out the 4 freighters first and then the initial fighters.
Only then did I disable and disarm the 2 Azrael transports. Then I waited for anything different to happen.
Last I attacked the Azrael transports, triggering the additional fighter wing's appearance as stated by the wiki. And I destroyed the transports and the fighter wing.
But it ended in the same result: the end-of-mission recommendations stated that I should have tried to find out what triggered the appearance of the fighters.