There Will Be Blood/WMG

Daniel Plainview didn't lie about giving Paul $10 000
While it's true he could have lied, but there are scenes between Daniel's meeting of Paul and him telling. In the beginning, while he threatened him, Daniel and Paul treated each other with the utmost respect. Daniel made it clear he would get "More than my money back." Should Paul not be truthful about the land he was selling info on. Paul took the threat in stride. When Daniel and H.W. personally go to Sunday Ranch and find that there is indeed oil down there. More than neither he nor even Paul anticipated. After buying the ranch and subsequent properties surrounding it, he makes a call to Fletcher complimenting Paul on the find. At this point on the off chance Paul was lying before, he probably still kept tabs on him and either through himself or his company gave Paul the $10 000.