Since the patch that fixed most issues on bots now they seem focused on getting all 4 bounty runes without any concern of their safety , you can pummel whichever bot is going to your team side to get the rune and since you are beating it the bot cant decide to go forward getting the rune or retreat for safety as long as the rune is nearby usually ending on a kill for you if a team mate doesnt grab the rune making the bot act normal again.