While that number also seems low to me, comparing the failure rate of a court case with a single line of code is a ludicrous analogy. I, a distracted and harried developer, will write hundreds of lines of code a day and not think twice about them, whereas each criminal trial is, for some period of time, the subject of undivided attention of at least one judge, two lawyers and a jury.

Errors certainly happen, but they're almost certain not to be dominated by errors of simple oversight, which explain the vast majority of bugs.