I'm assuming that the sharpshooter isn't going to leave the scene while something is happening on the bridge.  I'm also assuming that the sharpshooter knows that the merchant is a citizen and can recognize him.

>! A foreigner with a large cart walks up to the bridge as the sharpshooter is leaving.  The merchant and the foreigner meet in the middle of the bridge after 4 1/2 minutes; the merchant climbs into the cart and hides.  The sharpshooter returns, asks for paperwork, and the foreigner has none; the foreigner turns around with their cart, is not shot, and leaves with the merchant.

Or, less interestingly:

>! The merchant hides himself in his wares, which go out like normal (however that works--he certainly isn't the one taking them).