I have to agree with the court here. This isn't a case of cross pollination or the seeds drifting on to Bowman's land. If that were the case, Monsanto wouldn't have any standing since the farmer didn't know or intentionally try to reuse their product.
What Bowman did was buy seeds from a grain elevator betting that most of them were roundup ready, sprayed roundup to eliminate the ones that weren't and then replanting the surviving plants seeds. He intentionally was selecting plants that had the roundup ready genetic engineering.