Rather sad mood but I was attempting flawless GoS with my friends for shader. When getting pulled for second encounter I got a longer loading screen with a message of the error trying to reconnecting me and error baboon . Got pulled but just before the jump puzzle. Team carried on with encounter and we managed to finish whole raid without anyone dying. Unfortunately I was the only one who didn't got the triumph pop out. Even thou I didn't died at all, no tokens used. Destinytracker can be used as a proof. I didn't left the fireteam, we didn't lost my token.
Greetings!
Unfortunately, any form of error code or disconnect that occurs during a flawless run will void the flawless. The game recognizes it as you leaving, and the triumph wants the raid done from start to finish. You'll have to run through the raid again flawlessly and without error codes/disconnects.
Additionally, the BABOON error code is a networking error that usually indicates packet loss or disconnections between your network and Bungie.
https://help.bungie.net/hc/en-us/articles/360049195151-Error-Code-BABOON