This question already has an answer here:
According to this meta question/answer "on hold" questions will not accept answers.
But this SO question was placed on hold at: 2013-07-05 07:58:51Z but accepted a new answer at: 2013-07-05 08:09:38Z
Is this expected behavior?
Note, for clarity, that the above meta question/answer reference also states "on hold" questions will behave identically to closed questions.
From what I can tell, closed questions cannot have new answers posted to them after they are closed. (I'm trying to avoid the use of the word "accept" here because I think it is an overloaded term.)
However the example SO question I linked allowed a new answer to be posted to the question after it was closed (more than 10 minutes after it was closed, from what I can tell.)