Frustration and anger are the motivating factors I'm going for. Not necessarily toward the linesman, but just in general from the hit, and he directed that frustration outward on the ref.
There is no way anyone can convince me it was accidental contact or that Wideman "didn't know where he was". He was looking in the direction of the linesman the entire way to the bench; maybe not directly at him, but the ref was definitely in his field of view.
And even if we believe Wideman's statement that he was woozy and had blurred vision WHY would his first reaction be to deliberately cross-check someone? If he had merely bumped into the linesman I might be able to give him the benefit of the doubt, but he clearly took his stick in both hands, brought it to his chest, and pushed into the back of the ref. Nothing incidental or accidental about that at all.