As an MD, I'm not really sure what if any culpability Cuomo has here. It's a rock/hard place situation. No one wanted to touch any patient coming from a hospital COVID or otherwise early in the pandemic, and that leaves you wasting hospital resources trying to place a stable patient with nowhere to go that can meet their care needs (and exacerbate shortages of PPE, hospital beds, etc.). From an infection control standpoint, I imagine nearly all patients who were DC in that position, even if still testing PCR positive, were not infectious, although the scientific certainty at the time was much less. It is reasonable to consider whether his policies actually caused any harm at all. Nursing homes and other long term care facilities were destined to be infectious hotbeds regardless, and with NYC being an epicenter before having knowledge, protocols, adequate supply of PPE in place, etc., you would expect much worse outcomes than elsewhere. Even should Cuomo have done something wrong, the question here is more about was he responsibly acting on the best information at the time rather than judging by the results.
All this said, I'm only peripherally familiar with the information. My recollection involves some allegations of suppressing data about infections, for example, but I don't recall the details and may be flat wrong. Things like that would be a problem, though.