He said so in the first post, you just did not read carefully. He bought an asset, was filled and was hence long the asset. He then placed a sell stop order which he claims was not honored despite the price having moved below his stop price.
oh now it's a sell stop market order - are you sure you know?
sell stop, sell short, sell to open, sell to cover, sell, sell stop market, sell stop limit did i miss any? yea i did sell to close...
Some people (now on ignore list) have never experienced disorderly markets and claim they know so much and other are ignorant.