'Never' takes a man on - key, 'takes a man on'. Unsaid - without a starting advantage. 'Always' is actually right too if you only look at his recent performances - you'd probably have to go back to his loan spell to find a good cross. Front post crosses are easy, and they're speculative. They're never likely to result in goals when there's a defender on the front post, and every time he's hit those crosses that has been the case.
Maybe the winger should've been covering back but at that stage in the game they can't be expected to cover every single run, the full back should know that better than anybody.
The principles of defending narrow go out of the window the closer the opposition get to your goal. Then it becomes more about marking and stopping the most immediate threat. In today's case, the goalscorer was the biggest threat because he was in the most space and was the most obvious pass. I'll never slate a full back for half covering the wide threat when that threat is at least as large as any central threat, especially when the defence is more well manned centrally.