The fact that it hasnt showed up since could mean that he's tired of being shot at...LOL

I had a similar ordeal.
Last fall I shot at one in my back yard with my bow(40 yds). It too ran off and down its hole. I did check it out and couldnt find any blood, or my arrow. I just wrote it off as a miss and maybe the arrow skipped into the field, but I too have not seen the groundhog since. Since I didnt see blood I still call it a miss, but I do gotta admit it does have me wondering........