Eddie Jones was right when he predicted the support of an "extra man" would be crucial when England played Wales. Rather than the Twickenham crowd, it turned out be the television match official.
Wales were aggrieved at having a try ruled out during England's 12-6 victory which kept Jones' team on track for a third successive outright Six Nations title.
Jonny May's early pair of tries set England on its way to a record 15th consecutive home win in the championship.
But Wales could have had two tries, too. Scott Williams' legs were bundled into touch by England flanker Sam Underhill as he was sliding toward the left corner in the second half. But in the first half, the TMO ruled out a try for fullback Gareth Anscombe.
"He has one big call to make and unfortunately he's made a terrible mistake and at this level that's pretty disappointing," Wales coach Warren Gatland said.
England showed little sympathy after moving level on points with Ireland, after their main rival thrashed Italy 56-19 in Dublin earlier. A Grand Slam decider between the two in just over a month remains a possibility.
"I don't know why people say we're lucky with the refereeing decision," Jones said, "The TMO has all the time in the world to make his decision."
Anscombe appeared to beat England wing Anthony Watson to the ball in-goal but TMO Glenn Newman advised referee Jerome Garces not to award the try. The disbelieving visitors were forced to settle for a Patchell penalty.
His hand was there and clearly there's downward pressure"
Wales coach Warren Gatland
"I thought Gareth got there," Gatland said. "His hand was there and clearly there's downward pressure. It's human error, he makes a mistake, but at this level in front of 82,000 people when there's a lot at stake guys have got to get those decisions right."