It is a defeat that leaves Northants' hopes of qualifying for the quarter-finals in serious jeopardy with just one game left to play in the North Group.
The loss to Yorskshire coupled with Derbyshire Falcons' win over Lancashre Lightning, means the Steelbacks are now fifth in the table, and relying on other results - as well as a win in their final game at Leicestershire - to have any chance of progressing.
Things had started so well for the Steelbacks against Yorkshire as they reduced the visitors to two for two and then 11 for three in the fourth over of their innings.
But England prospect Harry Brook then counter-attacked with a superb 67 from just 31 balls to get the visitors in the game, before some late hitting of some ragged bowling saw the Vikings close on 190 for seven.
The Steelbacks' batters struggled badly in reply, with big-hitters Chris Lynn and Josh Cobb both going early, and they stumbled to 128 all out in the 17th over.
It was a bad night all round, but White was particularly frustrated at the fact Vikings were allowed to post such a big total.
“We have debriefed it, and yes they got too many runs," said White, who claimed three for 30 from his four overs.
"We had situations where they were under the pump and I don’t think we were ruthless enough,"
"We’ve had occasions like that in this tournament where we need to be more aggressive and positive and we sit back, which is disappointing.
"We speak about it, but it keeps happening, and if you don’t do that against good teams, they’re going to score runs.
"Brook’s a fine player, we all obviously know about Dave (Willey) and the other players they have, so we have to be a little bit more ruthless when it comes to it with the ball.
"This is a good deck here (at the County Ground), you can score quickly and they got too many runs.
“We need to find a way of igniting ourselves to really get right on top and not let them get away.
"You see in T20 cricket that can happen and they’re right back in the driving seat."
It has been a bad week for the Steelbacks who look to have thrown away a quarter-final place with three defeats in the space of four days.
But White isn't going to get too downhearted.
“Our batting just didn’t get going today," accepted the left-arm spinner. “But it is hard to be too critical of them because we have batted really well in this competition, and you do have innings’ that go that way.
"But we’re not all down in the dumps – we’ve played some really good cricket in this tournament, a really good brand of cricket, we just need to polish up on a few areas.”