I'm starting to think this could be some long-term fatigue, not anything recent. The first half of this busy schedule, all of the traveling from a ton of road games, and to be competing hard against some really good teams (enough to beat them in their own floor, no less)... I just think that whole long stretch caught up with them, and as it was about to finally wind down I think they subconsciously finally let themselves exhale and feel how tired they really were. You can accrue fatigue over a long period of time from high effor and/or low sleep.
High long term fatigue could account for the low energy/poor body language, the extra missed shots, and the less than sharp minds that can slow down assignments/rotations. I think it could be the biggest factor here.
And again the Hill/Granger injuries do no favors, plus now that it's a losing streak players aren't trusting the system as much because they badly want to provide some kind of spark, but what happens is unless they get hot, going away from the team gameplan otherwise backfires.
All-star break can't get here fast enough IMO.