Asked about the controversial drop on the 15th green last Friday, Williams told New Zealand's 3 News that, although he didn't think Woods was trying to "gain anything on the field," his former boss should have been disqualified nevertheless.
"From what I can gather, he took an illegal drop, signed a scorecard and left the course," Williams told the television station. "Under most circumstances that would result in disqualification. ... If the rules of golf are upheld, I believe he should have been disqualified."
Woods was deemed to have taken an improper drop on the 15th hole during the second round last Friday after his approach shot hit the pin and bounced back into the water. The No. 1 player in the world made a bogey-6 on the hole, which the following morning was revised to a triple-bogey 8.
"I don't think people should be able to phone in and have any kind of effect on a golf tournament," Williams told 3 News. "I don't think people should be able to sit back and have an outcome on a tournament.
"Tiger certainly wasn't trying to gain anything on the field there. Obviously he was frustrated and he mistook the rule between a red line and a yellow line and where you can drop. ... It was a mistake."
Williams — who returned to the winner's circle Sunday at a major championship for the first time since the 2008 U.S. Open — said he didn't fully understand the relatively new drop rule himself.