EC-135 isn't complicated???
It (and all other light twins that are capable of Category A) has redundancy and complexity to rival a Boeing 737.
When you compare it to a Cessna Mustang (their latest small bizjet), it's more complex in systems. And to get insurance on a Cessna Mustang, you'll do 25 hours of simulator training, plus a whole lot more in-flight training before they sign you off.
And that's before you consider the complexity of the mission - all Cessna Mustangs will takeoff and land on long stretches of paved, lit runway, with good navaids and well-established procedures. Most EMS missions don't know where they going to land when they take off, let alone have to worry about navigation, talking to a different type of ground agency on every mission, not know about wind and weather in detail when they arrive on scene. I could go on...
We delude ourselves if we don't think the helicopters flown are complex. And we need to recognize that the missions are equally complex.