Do you need to purposely fall back while defending to obtain all audio logs. I'm just missing two and cannot find them. I'm currently playing all the maps over and over defending, but no luck. Some I let myself fall back, but it just takes so long that I don't want to do it for every map.

I think someone on youtube might of just figured this out for me. You need to win on the very first primary objective while defending. I hope so. I'm off to try some more! Anyone want to confirm would be nice.

Alright, that was right. I just got my platinum.