If you isolate the statement and offer 0 charity then it is, but from the context and the following sentence it's clear that he a) either doesnt know exactly when the Mandate began or b) did simply mean Palestine but confused time periods which becomes apparent by the following sentence: "That all changed once the ideology that the land belonged to Jews began to make rounds following the conclusion of WW2...". So I think my interpretation is fair and charitable based on a holistic reading.