Question juridique clé
Whether the public-law appeal could succeed on arbitrariness, presumption of innocence, and in dubio pro reo
Solution extraite
No. The cantonal court's factual assessment was not arbitrary and did not breach the presumption of innocence.
Motifs extraits
The court may rely heavily on the appellant's own immediate statement; he did not claim to have checked rear traffic, and the finding that he failed to look back was sustainable.