There are many reasons to suspect the husband.
There is a bone scan where she had multiple broken bones that the husband in-name-only kept secret from the family for many years. The fact that Terri was planning to divorce Michael S. according to her friends. The fact that the friend she was out with the night of her collapse told her not to go home, but Terri said she would be alright that she would pretend to be asleep when Michael came home.
The fact that he didn't call 911 when she collapsed, but called Terri's father, who had to tell him to call 911, the fact that he did not give her CPR, even though he knew how, the fact that he told the jury how he would take care of Terri and use the jury award to provide rehabilitation for Terri, and then refused all rehabilitation for Terri, the fact that he "remembered" after the jury award that Terri wanted to die, the fact that he refuses to let her have basic health care like a gynecological exam or dental care, etc...
This is all traced to this one neurologist's ramblings.
It has been looked into and dismissed as BS.
As far as the rest of it, I wrote it off as gossip and perhaps worse.
Please don't get into that malarkey. If I were M. Shiavo, I would be slinging libel suits like darts.