It will be a very interesting case to see go to court ( I suspect Wilson will settle before trial, as an open court will open up their business operations to scrutiny they will want to avoid)
But if it did go to court I think Wilson would win based on the law cited, as at the time of the acquisition there was considerable competition for them (James smith- 850 places (400 meters away) , and Readings -900 places - 700 metres away)
HOWEVER, 6 month after the acquisition this competition was eliminated by the Kaikoura Earthquake.....
IMHO ( and IANAL) The Commerce commission really be arguing Section 36 , taking advantage of Market power....
http://www.comcom.govt.nz/business-competition/fact-sheets-3/taking-advantage-of-market-power/