Oooh yes! Good call.
The cooking of the books was to do with dairy records, iirc. I think he was trying to make the milk factory look more productive than it was, or something. If my memory's working, Charlie sussed it and grilled Rob about it, but never got the opportunity to take it any further before he was unceremoniously despatched to Scotland.
I believe he's still working for Damara though, so he could hear about Rob's return and start sowing seeds of doubt.
Charlie could also be instrumental in bringing the tampering with the culvert to light. He knows that the culvert was blocked with a feed sack, and he and Adam might put 2 and 2 together.
While the villagers might just tolerate a sociopathic rapist in their midst, if it came to light that he was also responsible for flooding half the village, he'd be totally persona non grata and could possibly even face legal action if it could be proved.
We really need a definitive map that shows where this bloody culvert is, too!
The bit of dead dog that ended up in the forage harvester is a bit trickier though. I can't recall where Rob was working then, I don't think he was at the Bridge Farm shop.
This corner of the forum needs an official archivist to keep track of all this stuff!