If the air gun is metal (usually the case) and is held in your hand, you allow the ions to recombine at the tip with separated charges during their travel, or dissipate charges in the tip through your body, no matter what hose it is.
So i´d say the problem is no bigger than any ESD precautions in general than for handheld air compressor setups. Should you not have any other ESD precautions, like a wrist band, dissipative footwear, ..., you get the same problems.
Of course the air flow does lead to more charges being separated through friction than without, but no one said how much rubbing on the carpet is acceptable before handling parts to compare the two forms of charge buildup - it can only be avoided by using ESD protection.
I used to see techs vacuum out computers and afterwards the 4000 series CMOS IC's would be damaged.
Heard such cases as well. As far as i understand it, it will always be the the tool that has most of the charge built up, the air molecules themselves do not carry enough at once to have an electrostatic discharge that results in failure, right?
So contact between tool and component is needed.