Pushpa's standout sequence is allu arjun pushing a large number of red sanders into the reservoir before collecting them at the dam. In that scene, the wood logs float and make their way all the way to the dam. In one scene of Rama Rao On Duty, the filmmaker emphasizes how the red sander wood is so dense that it will sink in the water, and the smugglers use this property of it to conceal themselves beneath the surface.
In actuality, the only kind of wood that sinks in water is red sand. It appears that Sukumar, the mastermind, overlooked a tiny bit of logic in Pushpa. Anyhow, a minor logical error doesn't matter since pushpa is already a big hit.