Before they do that, he picks up a cell phone and calls a bad guy with it. When he is beginning the conversation, the cell phone antenna is down. They change to a different angle, and the antenna is up. The German that is being spoken is mostly rubbish - the gist is right, but it's fairly random. Since this movie was supposed to take place in NY city, there should be a building somewhere.
Action can occur on one bridge, while they film it from the other bridge.
I actually have, in case anyone's wondering about it. If I remember right, they've got a 5, a 3, and they need 4. Fill the five, tip it into the 3, leaving 2. Empty out the three, and put the 2 in it. Then fill the five, and use that jug to fill up the remainder of the 3, which will leave 4 in the 5 gallon jug.