THAT'S the trouble with a trip to the Barbours. One false move and it can be game over.

Sweeney Todd wasn't needed to remind anyone Welsh of that at Twickenham on Saturday.

Wales cut their own throats with ill-discipline and inaccuracy against an England side that was nothing special.

The fatal nick came in the 34th minute when Alun Wyn Jones was dispatched to the sin-bin after tripping Dylan Hartley in front of referee Alain Rolland. While the youngster was off the pitch, England piled up 17 points, turning a 3-3 scoreline into a 20-3 lead, an advantage Wales ultimately failed to claw back.

For Jones, a rugby player with a law background, it was a harsh lesson in the realities of crime and punishment. Transgressors pay the price, sometimes punitively.

In a way the 24-year-old might have cause to rue how the rugby fates conspired against him.

Two years ago in Dublin, with Wales playing for a Triple Crown, Martyn Williams stuck out a leg and brought down Eoin Reddan as Wales scrambled desperately to halt a promising Ireland move.

Williams was binned, but Wales didn't leak two converted tries and a penalty like they did in front of the Barbour-clad hordes in London. They went on to win the game and Williams was hailed in some quarters for being streetwise.

This time,Warren Gatland witheringly described what had happened as ''absolutely stupid''.

Making the episode more frustrating from a Welsh point of view was that it needn't have happened.

It wasn't as if Wales's line was in imminent danger.

Hartley was going nowhere and would have been stopped a couple of yards up the pitch had Jones not made his fateful intervention.

The Lion did what he could to try to atone, setting up Adam Jones's try with a pass that a centre would have been proud of, stealing an England ball in the line-out and tackling and carrying strongly.

But it was like a goalkeeper who saves 20 shots and lets the 21st through his legs. People remember the blunder. Even so, it would be a mistake to ignore everything else that was poor in Wales's performance.

Jones wasn't to blame for the line-out woes. Those were largely down to poor throwing.

He wasn't to blame, either, for the mediocre Welsh kicking, chasing and catching, the ineffectual link at half-back, or the lack of invention Gatland's team displayed until James Hook started sprinkling around magic dust in the final quarter.

Wales also made 19 errors and failed to win a turnover.

So the Welsh coaches have more on their plate this week than the necessary business of making sure Jones never again perpetrates such a thoughtless error.

The Welsh line-out will need the most attention.

There had been disruption beforehand with Matthew Rees and Gethin Jenkins dropping out, but the set-piece still should have functioned better. Much better.

Steve Borthwick has been known to stay awake until dawn trying to crack opposition line-out codes, but he could have been tucked up in bed early last Friday night and England would still have won a glut of ball, so off beam was Wales's throwing.

No side can expect to win an international when winning only seven out of 12 line-outs. It was like going back to the bad old days when Welsh throwers seemed to operate on long wave and the jumpers on short wave, with the lifters on FM.

The visitors' work with the boot wasn't great either, notwithstanding one excellent cross kick from Stephen Jones which Tom James should have made more of.

James is strong and a hard-runner but he needs to develop composure. He had a chance to claim a try after the ball bounced off his chest as he went over the line in the second half, but he failed to apply the finish.

At Test match level, such misses are costly.

The defeat means Gatland's team face a character test over the rest of the Six Nations.

The coach hit out at negativity in Wales before the game against England and pointed out that his side had won eight out of 10 championship fixtures over the past two seasons. But in 18 games since their 2008 Grand Slam they have lost nine and beaten only four sides — Australia, England, Scotland and Argentina — in the top 10 in the world rankings.

So statistics can be double-edged.

What is clear is that Wales need a good result against Scotland this week because they do not want to be going into their games against France and Ireland with confidence shot.

That being the case, Gatland is certain to remind his players that with barely five minutes to play at Twickenham they were within a try of becoming only the second Welsh team in 22 years to win at England's base.

He will also no doubt accentuate the positive by underlining to Adam Jones and Paul James how they had the upper hand on their English counterparts in the scrums.

He might also hail Jones's superlative try-saving tackle on Ugo Monye and his second-half try — only his second for Wales.

Any sweep of the pluses would mention the hard-working Ryan Jones as well, and the remarkable defensive effort of Martyn Williams, who made 18 tackles, one shy of the total achieved by England's entire back row.

And scanning a DVD of Hook's best bits from the championship opener would underline to Wales's players that they have a performer in their ranks of truly sublime quality.

Hook may harbour hopes of eventually returning to No. 10 for the Ospreys and Wales. But this season he has played some of his best rugby from midfield.

His try was special by any standard, involving strength, pace, guile and balance as he dummied Mathew Tait, pushed back Tim Payne, stepped past Jonny Wilkinson and sent a jolting hand-off the way of Danny Care.

It isn't an exaggeration to say few players in world rugby could have claimed such a score.

But any hopes Wales had of victory were dashed when Delon Armitage intercepted a Stephen Jones pass to trigger a long-range move that Tait did supremely well to turn into a try for James Haskell.

Within minutes Gatland was on TV venting his anger over what was immediately being styled as Jones's moment of madness. Cyberspace wasn't slow to join in. In fact, there may have been aliens in outer space who wanted to add their twopenn'orth.

But that's Twickenham for you.

It can hurt.

Having to fork out £30 to park on a kerb was painful enough — eye-watering, in fact.

But you suspect if that's all Alun Wyn Jones had to feel down about on Saturday evening he would have taken it every time.