Undoubtedly Cohen’s passport doesn’t show he was in Prague. Might he have been there otherwise? Sure—if he and one or more foreign governments wanted to hide his tracks.
I don’t think we know enough from this report to conclude that he was, however.
His passports records also indicate he did not leave or enter the US during the time period claimed by the dossier. May Bush Sr. flew him surreptitiously in a military jet.