I don't know that it's a matter of big brother. A huge amount of inexperience and immaturity in that cockpit. That the FO was texting while flying the leg makes his conversation very relevant to the investigation, especially as his commentary is directly related to his state of mind and the captain's, as well as both their actions.
The FO's commentary makes me deeply suspect of his account, however, given the high level of ignorance and his inexperience.