He did not return to Berlin until March but he still did not seem to have read Friedmann's letter. Only Krutkov, when a colleague of Friedmann's from Petrograd, met Einstein at Ehrenfest 's house in Leiden in May 1923 and told him of the details contained in Friedmann's letter did Einstein admit his error.
Siya ay hindi bumalik sa Berlin hanggang March ngunit siya pa rin ay hindi mukhang nabasa Friedmann ng sulat. Krutkov lamang, kapag ang isang kasamahan ng Friedmann's mula sa Petrograd, matugunan Einstein sa Ehrenfest 's house in Leiden sa Mayo 1923 at sinasabi sa kanya ng mga detalye nakapaloob sa Friedmann sulat did Einstein umamin ng kanyang pagkakamali.