Dragon might be glitched

one of my teammates warded dragon in the middle of the little opening in the river, we began attacking the dragon and had to disengage due to the enemy team's presence. The dragon came out of his den and on his way back, and the dragon started shooting at my teams' ward with what I would consider his auto attack, the breath from his mouth that charges up... The enemies were not in the vicinity but they could see due to a stealth ward of their own in the pit. Dragon kept trying to attack our stealth ward but before the ward ran out of time, my team killed the dragon. There was a riot employee (the first one I played with so far) in that match and they recommended someone put this on the boards...as they weren't sure if this is a known bug.