One way that psychedelics could enhance error is by causing one to mistakenly forget or bypass their normal level of critical thinking or conditioned thought processes that normally take place in the occurrence of a sudden insight. These critical thinking processes are, for many of us, consciously trained priors that function as a way of regulating our critical thinking in everyday life. It could be that psychedelics eliminate these priors as well, but it doesn’t seem that our conscious thinking ability and memory are necessarily impaired by these drugs, so many scientists or philosophers wouldn’t necessarily be destroyed by their effects.
Often why we feel we've thought of so many genius ideas to "solve all the worlds problems" while on mushrooms, only to find, if we happen to write anything down, that they're ridiculous under normal conscious scrutiny.