In reply to Luke_92:
Agreed with others above, I think it's a decent amount of slack. Also, it looks worse than it is, as the belayer is much closer to the camera than the bolt. So whilst it looks like he's stood below the bolt with a lot of slack out. He's actually stood quite far from the bolt with a very reasonable amount of slack.
Great bit of climbing! We were on one of the routes to the left, and hadn't realised what he'd ticked. Nice not to have over the top victory cries!