I do feel bad for Arnold. He was a great prospect, very talented, and earned his five-star rating. I think his development was set way back by the terrible OL, no WRs due to injury, and a new OC that runs a system he hadn't played in before.
That said, if you fumble on simple runs straight up the middle and bounce routine balls, you have to be pulled like he was. And Hawkins does look good. I do think the game situation helped him some, but at least he wasn't making basic mistakes.
It is a shame for Arnold though that he couldn't ever settle in. He looks like he's about to jump out of his own skin, he's so nervous and jittery.