cheap shot shares the universal stun DR timer with other "generic" stuns such as charge, intercept, conc blow, HoJ, druid bash, druid pounce, war stomp, and i believe intimidation.
most of those dont come up very often, especially since cheap shot is usually applied to a target before the warrior charges or the druid pounces or paladin hammers, but its still nice to know. knowledge is power, and knowing that your CS might be 1s instead of 4 thanks to a pair of shared stuns before it means you can choose whether you want that 1s stun and the 2 CP or if you should opt for a garrote instead.