Used to, currently did, it didn't change Percy's statement in any way. He wanted no pity from anyone. But this wand-waggler wasn't moving out of his way. While Percy could hold his own in a verbal spar, he had no wish to enter into a physical confrontation, though he could if he needed to - he had the scars from the Battle to show for it.
But how could he go and save face? And if this did turn physical - he shuddered in disgust - the idiot would likely enjoy it too much. He had to do something, though. He couldn't simply stand there all day.
At the end, it was the reminder that he had work to do that pushed him forward. He side-stepped his brother's friend, making certain not to touch him, and with a final glare, made his way out of the store.