Did you find any kicked up brush in the direction that he went? If you hit high.. did you check on foliage for blood.. not just on the ground. Sometimes if you get a high hit.. the body cavity has to fill w/ blood before is starts making it's way out of the body. From the blood on the arrow.. it looks a little dark which would indicate a possible liver hit to me.

The way we track difficult blood trails is that we start at the location where the animal was hit.. then one person stands there.. and another person or 2 circles the area till some sign is found. Then go to that sign.. and start over. Being very careful not to kick up the brush any more than nec. Like I said earlier.. make sure to look at more than just the ground.