It's not like the system he was cracking was very secure. It has to be regularly openable with just a piece of metal, with tolerances so that when your key teeth wear down over the years it still works.
A pin/tumbler lock can be made considerably more secure against the attacks that work very quickly than most of the ones found on houses in the US actually are. Simply using security pins will significantly reduce the effectiveness of lockpick guns, rakes and bump keys.
In short, standard pins in locks only have one place they're likely to stick when manipulated under tension: the shear line that allows the lock to open. Security pins have additional grooves machined into them that will make the pin stick at points that do not result in the lock opening. It's still possible to pick locks that have them, but it often needs to be done one pin at a time, which is usually slower and tends to require more skill.
In short, standard pins in locks only have one place they're likely to stick when manipulated under tension: the shear line that allows the lock to open. Security pins have additional grooves machined into them that will make the pin stick at points that do not result in the lock opening. It's still possible to pick locks that have them, but it often needs to be done one pin at a time, which is usually slower and tends to require more skill.