The stress of the new additions to the flock can put a hen off her laying routine. Heat waves can do it. Also, individual disruptions in the laying cycle can deliver mixed signals to a hen, and her egg may want to come out during a period when she isn't geared up for it. These all should iron themselves out.
However, if the laying from the roost continues, and you know which hen it is, you might try calcium supplements to help reset the laying cycle.