If your toes get banged up while hiking you can always hike in the sandals. Recently a member of our group mashed his toe and hiked the remaining 16 mile in his sandals. The sandals don't give as much support but they will keep you moving. Also, they are great to wear around camp to relax your feet. The last two trips that I have been on has required that a member in the party use a painkiller due to an accident.
Accidents are quite common in the backcountry.
Everything from sprains to broken bones can occur. If there is the need, the pills can keep the person somewhat comfortable until they reach help or help can reach them. Water can make or break a backcountry trip. If there is not reliable water sources in the area be sure to carry more than you need. The added weight is nothing compaired to the problems that can come from lack of water.