Hiding in the dumpster was hardly a good option, but it was the only one, Billy reflected as Queenan tried to contact Dignam. So far at least, Billy having second thoughts about allowing Queenan to act as a human shield was paying off. They might even have made it out on to the open road, but the gang would have left guards at the entrance, and those in the building might have realised what had happened and decided to return to the entrance.
Billy suspected that although some the gang had reached the roof in the lift while the rest of the gang had come up the stairs to just a floor below, it must have taken them some time to figure out that their prey was not in the upper three floors. By this time he and Queenan had reached the ground and run around the side of the building. He had then spotted the dumpster. Billy had jumped inside, pulling Queenan up afterwards; fortunately it was only half full with contractors dry waste.
Being inside a dumpster might not be good for reception, but Queenan had now made contact with Dignam. Fortunately, Dignam was now near to the surveillance radio operator. Pushing the operator aside, Dignam ordered the surveillance team to protect Queenan in the dumpster outside the building. The surveillance team had already downed the guard that the gang had left with the cars and had charged inside, so they needed Dignam's message repeating before they were willing to break of and go back outside.
Sullivan had desperately texted Costello to abort, but Costello's attempts to contact the gang did no good. However, the shoot-out with the downstairs guards had distracted the gang, who now decided to exit the building as fast as they could, taking the injured guard with them.
Dignum had also requested backup, but by the time they arrived the gang was long gone. The backup team found the surveillance team with Billy and Queenan at the dumpster. Queenan had now grasped the situation, and told Dignam to find out the names of all cops involved in the surveillance operation, or who had been in close proximity. That included Sullivan and his hangers on.
Queenan also told Dignam to "roast Sullivan over a slow fire" in order to get the name of his "source", and to get an emergency ID for Bill in the pipeline. Queenan placed little faith in the value of Sullivan's source, while Billy placed little faith in either Sullivan or a source of what was probably Costello misinformation. But how could Costello be certain that Sullivan would take the bait, unless ...
The remainder of the ride back to SIU headquarters was a relief to Billy, though lack of a clean extraction was bound to cause him security issues. Queenan was in a fury with the damage that the mole was doing, now the mole was compromising undercover operations. Sullivan's stupidity was going to result in him receiving some real stick.