This episode references "Cantonese" writing. Cantonese is a spoken dialect, but used the same characters as other Chinese dialects in the 19th century. The "Cantonese" characters shown are actually simplified Chinese, something that only became common in mainland China during the the mid-late 20th century. Anyone even remotely familiar with China - let alone a scholar, would consequently have known the 19th century gold watch using 20th century characters to be a forgery.