(CBS News) PRETORIA, South Africa -- One of Nelson Mandela's grandsons said Friday he expects Mandela to be discharged from the hospital soon. And the man who succeeded Mandela as president, Thabo Mbeki, said in a radio interview that Mandela's health is improving.
Mandela, 94, has been in the hospital for two weeks, fighting a lung infection.
However, what CBS News is hearing is completely at odds with statements from Mbeki. Sources tell us that Mandela's liver and kidneys are functioning at 50 percent, and he had a procedure to repair a bleeding ulcer and another one to insert a tube.
We're told he hasn't opened his eyes in days and is unresponsive. We also understand that Mandela family members are discussing just how much medical intervention is enough for an old and very sick man.
CBS News has also uncovered more about what happened the night Mandela was taken to the hospital. We now know that Mandela went into cardiac arrest that night and had to be resuscitated.
He was taken in the middle of the night in a military ambulance to Pretoria, but the vehicle broke down, and a seriously ill Mandela had to wait on the side of the highway for over 40 minutes for another one. We don't know why it took so long for a second ambulance to arrive, but he was eventually transferred to a second vehicle in freezing winter temperatures.
The South African government has confirmed there was engine failure, but it says great care was taken to ensure that Mandela's health was not compromised and that his doctors were satisfied the former president suffered no harm.
However, cardiologists we spoke to said any delay -- especially for a man that old -- is cause for serious concern, and while it is difficult to assess, could have had an impact on Mandela's condition.
© 2013 CBS Interactive Inc. All Rights Reserved.