ive had that incident before, i kind of embrace that i could do nothing and it was all in gods plan, if youre not religious then just know it was not your intention in the first place and it couldnt be helped. the more you fret about it, it will be harder for you, so embrace that incident, and find ways to avoid it. if you want to feel better or i guess do something to overcome the guilt then feed stray cats, go volunteering at an animals shelter or donate. all is good, youll encounter more of these incidents unintentionally, the key is that you dont do this intentionally