Well, I suppose anything is possible; I, too, had not heard about any issues drinking out of a hose or water gun. My only thought would be to run the water a bit to clear out any stagnant water in the hose before drinking any water.
Maybe because as a kid, I did all kinds of things like that--drinking out of hoses, and public bubblers (water fountains, some people call them). Both of the above could have been at home, at a park, or at the schools. As a kid, I never gave any of that a second thought: if I was thirsty, I'd go get a sip of water. I even recall going to restrooms (if there wasn't a bubbler around), turning on the faucet in the sink, and sort of cupping my hands underneath the water and drinking water that way. Wow. I just now realized how uncouth I was!
![Hilarious :hilarious: :hilarious:](/styles/default/xenforo/smilies/hilarious.png)
(Although, I was never thirsty with my class-less ways!
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
) But you know what? In all honesty, I don't ever recall any problems resulting from any of it. I wouldn't do any of the above now, but can't recall any detrimental effects from years ago.