When we are trying to help a person who is triggered, it is critically important to start with making sure our own relational circuits are online, and then offering attunement, before suggesting that triggering might be contributing to his distress. Making sure we are in relational mode and then offering attunement helps the other person get back into relational mode, and this makes it much easier for him to surrender VLE confabulated explanations and acknowledge traumatic implicit memory. Helping him get back into relational mode will also make it much easier for the two of you to work together, as a team, to care for his trauma. As Charlotte and I have examined this point in our relationship, we have noticed that things go MUCH better if we truly attune to the other before addressing the question of triggering; and we have also noticed that things consistently go badly when we do not start with attunement.
No matter what kind of interpersonal difficulty we are dealing with, simplifying the system by eliminating any triggering, immaturity, or other dysfunction on our side will always help.
See chapters 24 through 27 for additional explanation, and a variety of true story illustrations.