My wife and I got caught up in that mess as well when we returned from VCE on IB on June 27. People were trying to crowd into the line and it got ugly. We had two and a half hours to connect from terminal 4 to 4S and yet arrived at the gate five minutes before they started boarding our flight. We hurried as fast as we could, but the distances are significant at MAD.
There were only one or two people directing the line, and they were doing very little to help. However, one of them did say that this had been going on for about a week.