What surprises me, watching the external video, is the speed of the take off and particularly transition to forward flight and presumably attempt to pick up translational lift. There was little evidence of the cautious approach necessary to give an "out" to a potential situation of loss of lift.
On the assumption that the acft was indeed power and TRA limited, I would have expected a much more defensive approach to the problem. If you can't at least hover OGE (which was going to be essential to get out of this bull ring) you are not going to have the power to translate to forward flight without losing altitude, so I would have adopted a Cat A helipad profile of slight reverse climb to a height (eg 150ft) that would enable me to get to a point where I could trade height for speed as translational lift was achieved and clear the structures around.
If on the initial climb over the bull ring there wasn't the power and TRA to maintain the climb on heading to effectively CDP it could have been put simply back on the ground. Yes there can be the option of unloading the tail rotor and I've used this to good effect in the past, but this is not the sort of thing to be considering in this high profile case - or anything resembling Public Transport.
Of course we might all be wrong and there may have been a mechanical failure, but even then the departure technique gave little room for coping with any such occurence.