Just a quick Wikipedia check here:
The case drew worldwide attention and is widely misunderstood to concern what happens when farmers' fields are accidentally contaminated with patented seed. However by the time the case went to trial, all claims had been dropped that related to patented seed in the field that was contaminated in 1997; the court only considered the GM canola in Schmeiser's 1998 fields, which Schmeiser had intentionally concentrated and planted from his 1997 harvest. Regarding his 1998 crop, Schmeiser did not put forward any defence of accidental contamination.
Well researched indeed.