Couldn't reassemble chainsaw - solved

All right, so there was a reason why I could not reassemble the throttle trigger lockout on the saw. I just called an authorized repair shop to ask them what exactly I was doing wrong. It turns out a spring is needed there which I had totally missed. The guy said if somone opens a saw without knowing about that tiny spring inside, the spring will pop out and get lost, guaranteed. That's indeed what must have happened to me. I didn't even see anything was there in addition to the plastic part. He will custom-order and install the spring for me in early January.