If you mean the bottle isn't held properly in to the asa then it is completely safe. if it 'falls out' of the asa the pin closes on the reg, and your bottle falls to the ground, end of story. If you were to somehow snap the top flange then you would have a lot of air piss out of the bottle really quickly but again its not like its going to explode or something. unless you managed to snap the entire regulator off in one clean swoop, to allow a bottle full of air at 4500psi come out at once (aka a rocket) then you aren't going to have anything dangerous. they are designed this way nowadays with safety measures built in to allow for crazy things.
cheers for the reply but the bottle has been freed from the asa just clamped it up at work and got it out with reg in good condition to my surprise but looked at the asa and it was fuked so i chucked it in the bin cheers for all the help