Reusable as long as the material and straps are not torn. you just replace the gas cartridges. As for what happens if u accidentallly yank it getting off the bike, I don't know for certain.
Worst case: we all have a good laugh at your expense.
Best case: the sensor is linked to speed as well and won't deploy under say 20kph.
call a dealer and ask. Or, i'll let you know when i get mine over the winter.