Right.
All of those parts have proper names.
None of those proper names include the word 'joint'.
And while the trigger does 'control' the hammer, I've never heard of a part called the 'trigger control'.
Kind of like how you can spot a whuffo because they use incorrect terms, you can spot a 'firearm ignorant' writer the same way.
I'm not saying the report was incorrect, I'm saying the news story had a lot of terminology errors. Not unlike the news reports of airplane or skydiving accidents.
That's why I'd prefer to see the actual report, not just news stories about it.
Not super likely, but it's really hard to figure out what happened & why with crappy information.