Electronic Line Calling Defended

Electronic line calling is being defended by it's creator in today's Times of London

In the third game of the fourth set, with Roger Federer a break down and
serving at 30-30, he did not play at a ball near the baseline. He thought that
it was out, the line judge thought it was out, the umpire thought it was out and
a BBC freeze frame seemed to confirm this, too.

[...]

Hawkins said that the ball had landed in by 1mm. He claimed that the naked
eye was deceived because of the way a tennis ball compresses and skids on
landing.

“The ball will be in contact with the ground for about 10cm,” he said.
“In the very first impact, it will compress so that the bottom half is flat.
Then it will start to roll and skid and uncompress. The freeze frame the BBC
used showed the ball about 7cm after it touched the ground.” He said tests had
showed that his technology was accurate to within 3mm. “The ball was definitely
in,” he added.

Hmmmm, how do you know the call was in by 1mm if the error is +/- 3mm? Any engineer knows that if the result is within yuor margin of error you really can't make the call. The ball might have been 2mm out. But, regardless I doubt that Federer or the umpire could distinguish that difference.