The injured one was Bald Jūbē, the very first person Harano encountered after he landed in the Middle Ages of Japan.
This guy just had the worst luck—went up the mountain just to dig wild veggies, spotted a big bird with flashy feathers, and got all hyped, thinking he could make some easy cash. Sneaked over and shot the bird with an arrow, but the bird escaped wounded. Then he began a wild chase, three times, five times—never caught the bird, only to end up rolling down a steep slope, getting banged up all over, covered in blood and bruises.
Thankfully, being old and sly, he instinctively curled up while tumbling down, so most of the blood and mangled flesh was just scrapes and bruises—the worst part was a broken leg.
Of course, that's if you were in modern times. In the old days, there were no antibiotics—heck, the word wasn't even invented until 1940, forget about 1551. A wound infection could still totally kill him here.