Cricket has a problem with ball tampering that goes much deeper than this one incident; I saw an article late last week (which I now can't find) that essentially admitted that umpires have been turning a blind eye on "minor" ball tampering that has become systematic in the sport. It's this global culture around "acceptable" forms of ball tampering that then naturally leads on to someone being naive enough to take a risk on "unacceptable" forms of ball tampering.
Found it: http://www.espn.co.uk/cricket/story...ode-conduct-ball-tampering-set-bigger-offence
Some very telling quotes here from the head of the ICC itself, which essentially echo the exact point I've been trying to make in this thread.