Here’s what Einstein answered to Physical Review when they came back with comments from referees:
We (Mr. Rosen and I) had sent you our manuscript for publication and had not authorized you to show it to specialists before it is printed. I see no reason to address the – in any case erroneous – comments of your anonymous expert. On the basis of this incident I prefer to publish the paper elsewhere.
P.S. Mr. Rosen, who has left for the Soviet Union, has authorized me to represent him in this matter.