Ender Dragon Glitch

Me (LeWaffleLord) and my stepdad (Snuffleupegus) were playing the 1.9 15w51b snapshot on a LAN server together, (with cheats enabled) we finally made it to the end and killed the enderdragon as we did when the exp was falling, I fell through the portal and Snuffleupegus died. We went back to the end to find another dragon flying around with no health bar, the dragon egg was on the portal still, so we decided to kill new enderdragon and we got more exp but the dragon egg disappeared.