We have to consider what was already entered into the logs as we watched, and what might simply have been omitted. Basically 99% of the log material is clearly dictated well after the fact - in the earliest episodes, it's even in the appropriate tense for such narration. And many of the adventures would be way too hectic to allow Kirk to dictate anything until the credits roll. But some things do get into the logs as the episode unfolds, even though they really shouldn't be there where Starfleet gets to read them.
Regarding "Space Seed" we don't actually know that Kirk falsified his log. He could well have been completely upfront with his log and then Starfleet took it out of his hands--"We'll handle it, Kirk."
If Kirk did falsify his reports in that episode, that would entail all the goodies:
- Erasing already dictated log entries and associated other recordings
- Lying to Khan about making an official record about the proceedings
- Neglecting to dictate anything at all about the eventual outcome of the adventure
- Destroying physical evidence left behind by Khan
- Asking crew (in this case, probably every single one of the 430) to stay quiet and lie if questioned
- Creating a relatively extensive cover story of what the ship was doing in all that time and why she expended the resources Kirk in fact gave to Khan
However, the extensiveness of dishonesty there isn't an argument against Kirk doing it. In for the penny, in for the pound - Kirk
would have been capable of all of the above, and his colleagues could well agree to it all as well.
Well, technically, they did.
Regarding this, log entries supposedly are accompanied by visual records - at least of events taking place during alerts at key locations such as bridge or main engineering. So "technically" wouldn't help - in order to keep the secrets, Kirk
would have to erase and/or falsify all sorts of records, not just mince words.
Timo Saloniemi