Freddie was faking injury when he was being arrested. Here’s a video that starts where it shows Freddie standing on the back of the van before they put him in. He wouldn’t be standing like that if his legs or neck were injured.
https://www.youtube.com/watch?v=7YV0EtkWyno&feature=youtu.be&t=2m21s
This would not excuse putting him in the van loose; but again Nero had no influence upon that.