Natalie Wood Captain passes lie detector test: Does it matter?

Captain Dennis Davern, who was driving the boat the night that Natalie Wood drowned, has accused her then-husband Robert Wagner of telling him not to call the Coast Guard or turn on the searchlights after Natalie disappeared from the boat. Allegedly, he took a lie detector test in 2008 to prove that he was telling the truth about this troublesome detail -- and he passed.

TMZ, however, reports that the polygraph test -- which said Davern was not lying when he said that Wagner told him to cover up what happened that night -- may not be permissible as evidence in the now reopened investigation into the mysterious death.

Davern was allegedly drunk the night that Natalie died, and TMZ's polygraph expert says that skews the results. "If you believed something occurred, you would run truthful. It doesn't mean it happened," he says.

Davern admits he had been drinking scotch and wine when he was alerted to Natalie's disappearance.