With everyone focused on clearing out and no obvious suspicions about who might be leaving the streets closest to the market, they're able to put a fair amount of distance behind them relatively quick. The further they get, the slower Ozymandias allows their pace to become until he feels it's safe to stop both in terms of the military presence and Waver's grip on the rational portion of his mind.

"Are you hurt?"

The crowd wasn't exactly gentle with Waver.