This oversimplifies things a little.
Many things can trigger your brain to react in a similar fashion than during a traumatic experience.
You can also be aware that the experience is not the same or unrelated, but you'll still get a panic attack. Most likely because the actual anxiety or panic is not caused by your thinking brain.
That's exactly what the source said.
This works well, as long as not you’re not still in Iraq at risk of getting hit with IEDs.