William the herbalist

[finalheadshot]

So the other day I found some plants for William and gave them to him and while he was speaking I shot the animal nearby. William got scared and stopped the scripted speech and I didn't have any reward. After that I found his camp several times, but he wasn't there, the camp was empty.
Today I met William at last, but he just don't want to have any business with me now. So does it mean that I am not able to have 100% completion? Or I need to meet him again and he would change his mind?