Leeson Street you mean.
Either way these work colleagues were there from at least 3:37.04 (one facing in the direction, talking to the MIB) and were still there at at least 3:37.40, with at least the MIB and one of the work colleagues looking into the building (and probably the person under the brolly). The Guards in their release said that the MIB left and went across the road after he talked to Deely, he clearly did not.
It should also be pointed out that the person with the umbrella came in from the right, so presumably was a short bit behind Deely with CCTV of that showing that person arriving in. There's just so much more that they have on this that they won't release.