Mallory-Weiss Tear after C-section

My niece had a c-section during which the Dr. pounded up and down on her saying the baby was stuck.  4 days later my niece died.  The death certificate lists the cause of death as sepsis and a mallory-weiss tear.  I have read up on these tears and they say it is caused by severe retching like coughing or vomiting (which she never had) or alcoholism (she never drank alcohol) and she was only 26 years old.  Could this have been caused by the Dr rupturing or tearing the stomach from the esophagus during the c-section?  Her stomach was completetly black from all the pulling/tugging and pounding he did on her during the c-section.

Please help.