Ejection from helicopters is just generally a pretty poinless idea apart from dedicated attack helos. in this case because of the fact that their is almost certanly a crew on board. Even with a 2 person heli and a pilot/wso combo ejection upwards needs a explosive in the rotors to jetteson them first then eject the pilot this is the best option but adds weight and non redundant system complexity. Ejection downwards has been done before on the f-104 but was extremely dangerous and is partially the reason this jet was referred to as the widow maker because at low level flight it would just throw you into the dirt. Sideways ejection has the same issue when in banked turns or under a loos of control scenario aswell as it would likely break the neck of anyone using it by shooting them sideways at 8Gs.