I'd advise not to judge others' performance by the numbers reported by pools unless you know their setups. What you see isn't that other guy's exact hash rate but what's reported by the pool. He might have even more hash rate than what you have actually and he might be wondering the same thinking why he's getting half the shares with more kh/s.
Because pools report hash rate according to shares per a given time period which is also a mixture of luck + rig setup(hardware and software) + connection quality.