During crane assembly, Sixth Avenue sidewalk was supposed to stay open. It didn't. Who's accountable?

Before the crane installation/assembly that began yesterday, the notice stated that Sixth Avenue between Pacific and Dean Streets would be closed to through traffic for 15 hours, from 6 am to 9 pm, on Saturday, and for 6 hours today, from 6 am to noon.

The east sidewalk of Sixth Avenue was to remain open. However, as shown in the Instagram photo below, taken around 5 pm yesterday, it wasn't. This raises the ongoing issue of accountability. Why can't the state, developer, and/or city be monitoring this, and responding to citizen oversight in real time?

Again incorrect or misleading information is distributed by Pacific Park Brooklyn. The notice for crane assembly on Sixth Avenue that was sent out yesterday stayed the east sidewalk of Sixth would be open to pedestrians. It was not when I went by and it looks like it never was. Photo of 5 pm. #pacificparkbk #nyc_dot #nypd78thpct #bciza #tishman @nyc_dot @nycmayorsoffice @atlanticyards_pacificpk_report @greenlandforestcitypartners.

A photo posted by @pplegacy on Feb 20, 2016 at 2:24pm PST