There was no possible way for Emily to descend to the lower floors unless she wanted to have the forces chasing her and the cameras pointed at her. The security of every floor was quite strict, and the number of surveillance cameras made it nearly impossible for one to exploit any blindspot.
There is a shortcoming with Emily's barrier and that is the necessity of visuals; she cannot maintain her barrier if it's not within her vision. As such it becomes impossible for Richard and Laila to proceed towards the lower levels.
However, based on the information, Richard received from Laila, he knew he might be facing a situation like this.
Lost on choices, Richard said, "Laila, you are up."