Doug - sorry, must be a spelling mistake - Tristan is a male. Yes he was apparently standing separately from the activists when fired on with a powerful gas cylinder which the IDF say is as dangerous as live ammunition. The stated at the time that in spite of this, canisters cause 'less injury'?? than live ammunition.
U.S., allies conduct 1 air strike in Syria and 11 in Iraq against ISIS militants (Reuters)
from the article: Israel to reopen investigation into shooting of U.S. activist