In NYCFC's system, the run blockers have a specific man, so there is no passing them off. It's a zonal line of 4 (used to be 5) right at the 6 yard box that is responsible for clearing the ball. Everyone else is blocking runners or marking others outside the box. So there really is no confusion in this system.
This is correct and is why the blockers need to do their job. Last night being Ilenic. The service was also good enough and the end result was an easy goal for Philly.
The good thing is, that this doesn't happen often for NYCFC. As noted above, the two years they ran man-to-man, second most goals allowed in the league. Since they switched, the second fewest goals allowed in the league.