Hardeen wasn’t slipping a pair of handcuffs when he broke his wrist. The Player Newspaper reported that Hardeen broke his wrist on December 17, 1912 while cranking his car.
From the Player Newspaper:
Hardeen , the handcuff man , is in New York , laid up for repairs for a few weeks because of an accident which he suffered Dec . 17 . Hardeen was cranking his automobile when it kicked and broke his wrist . The injured member has been placed in a plaster cast , and it is expected will be strong and sound again in a few weeks.