You've gotten a bunch of answers that are different, because nobody is quite sure what your problem was.
If you had reached depth, gotten neutral, and then could not let air out through your corrugated inflator hose, that's a very strange problem. Most of the time, when people can't get the air out that way, they are not getting the orifice of the hose to the highest point on their rig. Especially if you are not accustomed to the short inflator hose and are putting it in bungie under the left chest d-ring, as is usual, it can require some determination to get that orifice up. That is one of the reasons that a lot of people who dive wings use the butt dump for venting, because if you are horizontal, it should either vent when pulled, or will require only a very small change to a head-down position to get air to it to release.
If, on the other hand, you had an inflator that was adding gas without you pushing the button to make it do so, disconnecting the LP hose was precisely the right thing to do. That hose does not participate in the venting; it is perfectly possible to use an inflator to dump gas with the hose disconnected. But it DOES bring the gas to the valve, and if the valve is leaking, gas can enter the wing. Why does this happen? Because salt and debris accumulates in the inflator mechanism. Inflators need to be serviced, just like regulators do, and they also need to be soaked and rinsed after diving, to help prevent the accumulation of crud.