I'm not a member nor a fan of Facebook or Zuckerberg, but I can't imagine anyone thinks it would be fair and just to draw any connection where the sole "evidence" is one benefited from someone else's misfortune. It can sometimes be suspicious but only when there is some other direct connection. It's called "jumping to conclusions" or "grasping at straws", usually on little or no actual evidence but mere speculation.
Is that what you would prefer, how you would like to be judged, in a court of Law or even in daily life?
Again I am sorry for your loss. I hope the two of you were not close.