When Drago No. 4 (played by Christopher Lee) takes off his dragon costume head the back of his hair is noticeably disturbed by the head, Then in the next immediate cut it's all neatly combed again.
When the four dragons open the doors of the golden pagoda marks in the wood around the door show that the same one was photographed for three doors seen being opened.
When the murdered Margret (Maria Perschy) is discovered lying on bed in her hotel room with her neck having been broken, we watch Commander Sanders (Rupert Davies) and Bob Mitchell (Bob Cummings) - after having examined Margret's corpse - in the foreground discussing their further proceedings to solve the crimes that have been committed so far in the movie. In the background we observe the dead body of Margret blinking with both her eyelids several times! A dead person surely can't do that.
When Magda first stands next to Bob at the club while she's singing, her mouth movements often do not match the phrasing of the song, such as her mouth cutting off a phrase while the singing continues.
When Sanders says to Chaio, "two deaths in forty-eight hours," he is incorrect as they would have known about three deaths at that time: Porter, the man in the harbor, and Margret.