I think it's just his math is bad. I'm doing about 8.5g/s on gminer, I think it's just reporting hashes a minute not second. If you divide 8.5 by 60 you get .141 and my accepted speed is hovering around 0.145h/sec on the pool.
Miner display graph per second, pool display hashes per second. To compute one hash miner should find solution, to find solution miner need compute on average 42 graphs.
Thus H/s ~ G/s / 42
Consider doing that on the client side. I'm sure you'll have less users confused.