My post was a bit ambiguous but Capn Bloggs got it right.
I am thinking that it was happening before but people were getting away with it because there was no damage to report.
And of course, when it happened, that was obviously wrong !!!
A similar incident happened in March 2014 in AEP when a Gol 737 clipped the RH THS of a LAN 320 :
ASN Aircraft incident 04-MAR-2014 Airbus A320-233 LV-BET