He and his wife may have been separated. I read that she wanted to change her last name and that of their children as it was so embarrassing to be a member of the Madoff family.
The separation and name changes were all orchestrated by the Madoff lawyers to try to insulate the brothers from the charges. But the brothers (and possibly the wives) knew what was going on and were on their way to being indicted by the IRS for tax fraud and other potential charges very soon. Their assets have been frozen and they are part of the civil recovery actions by the by recovery trustees.
The wife wanted a divorce, mainly for financial reasons...hoping that she and the kids could get some of the swag before her husband was sued...look, Rut got to keep $ 2 mill, so maybe she figured that the courts might let her keep a few mill as well. Mark made millions form the fraud. There is no way that the two sons didn’t know what was going on. I suspect that when the jig was finally up, they hatched a plan, with Bernie’s concurrence, (heck, it was probably his idea) that they woudl be the ones to turn him in, to deflect suspicion from themselves.