Yes but I doubt any drugs will kill 70% of people. In fact anything below a 60% death rate would be a net win, but certainly no-one is talking about such ridiculously high mortality rates from trial medications.
Within the realm of tested drugs, then sure, you won't find any with that mortality rate. But this drug had never been given to a human. There's no safe way to predict the exact effect it will have, and there is a realistic chance it could kill the intended recipient. This wasn't even trial medication, it hadn't reached that stage yet.