I posted this in the master bug list, but it's big enough that I decided to make a full post about it as well.
Currently Component Complete will always trigger after a dialogue box, if it is selected as one of the trigger targets, even if there are multiple other targets which have not been completed yet.
Steps to recreate:
Create 3 dialogues and call them Dialogue 1, Dialogue 2 and Dialogue 3. In each dialogue, select a costume and add the text "Dialogue 1", "Dialogue 2" and "Dialogue 3", respectively.
Place 3 invisible objects, and call them Interact 1, Interact 2, and Interact 3.
Set Dialogue 1 to appear after Interact 1, and change the trigger text on Interact 1 to "Trigger Dialogue 1"
Set Dialogue 2 to appear after Interact 2, and change the trigger text on Interact 2 to "Trigger Dialogue 2"
Set Dialogue 3 to appear after Dialogue 1, Dialogue 2 and Interact 3, and change the trigger text on Interact 3 to "Trigger 3".
Result: Dialogue 3 should only appear after all 3 triggers are completed (Dialogue 1, Dialogue 2 and Interact 3). However, it will in fact appear after either Dialogue 1 or 2 are completed, regardless of whether Trigger 3 has been completed.
I created an unpublished project called Test, ID: ST-HJSEIYWC8, which has a map called Dialogue Trigger Bug which sets up the above scenario.