The critical concept is "post-operative complication" ... what is this? I developed an incisional hernia about 6 months after my liver donation. Stanford became aware of this at a 1 -year followup, but it made no offer to repair the hernia; even though prior to domation it gave me the kinds of assurance that you recieved. I think Stanford's idea was that after a couple months post-op with liver funtion tests normal, it was pretty much off the hook.
The words that you recieve from transplant coordinators or docs do not really have much import. If liability for the follow stuff is important to you, get it in writing ... especially important to include a clause regarding how the 'post-op' condition's causation will be determined. If you leave it to the transplant center, there is, of course, a financial conflict of interest.
This being said ... I have absolutely no regrets about my donation. Even though it has been difficult for my sister; she has had 9 years of good quality life that she would not have otherwise had. My issues are inconsequnetial.