If he knew that wet cloth wrapped around two bars and a stick being twisted can bend the bars he wouldn’t have to break the lock to get out of a cell. If he knew this the lock wouldn’t be important. I don’t know how old this trick is…. but I do know it is at least 150 years old… just not well known. No it will not work on modern bars made of steel.
Yes it could have been a padlock, a lock built into the gate or just about anything from that time that a blacksmith could make.