The conspiracy theory is literally on his own web site.

genuine q tho, him generally funding the newspaper is different from actually deciding the piece? like same way you do not make the calls at your portcos

When you wife is going to the hotel room with a tall sexy guy, who is holding his hand on her ass... there is actually no guarantee that they are going there to have sex. 
Same logic

So all funding of media leads to bias, and not just bias but outright lying/misinformation?

That at least creates a conflict of interest, which by default leads to a reasonable chance of a bias. 
It is like relying on a weather forecast which has a 50% accuracy rate. It is just impossible to trust or not to trust such forecasts.