yes thats quite correct. but its because the tire or the ground is giving way not the locker.
if you look at the where the drive pin goes through the locker, the hole isn't round. its got sloped ends to it, ie a ramp which acts as a caming surface. the drive pin pushes each half of the locker out to keep the teeth of the locker in mesh.
the only way for the locker to unlock is for drive pin to come off the ramp which then allows the half of the locker to slide over and disengage its teeth.
btw going uphill is also the worse situation because you always have power on.
very difficult to coast when powering up hill.
thats why i've taken my rear auto locker out and fitted lsd back in.
Oh ok, nice to know... i was going to rebuild my rear diff but i thought a locker would be a cheaper alternitive..
So go the lsd ya think?