SEATTLE, Wash. (AP) — Boeing’s defense of its actions in light of last week’s release of text messages by senior company pilots is standing up.

Regulators and lawmakers were outraged when the messages appeared to show the pilots were worried about the new flight control system on the 737 Max as early as 2016.

Boeing responded that the messages concerned the behavior of an early and incomplete Max simulator and not the flight control system itself.

The Seattle Times reports that an analysis by outside experts finds that appears to be true.