How was this answer posted ten minutes after its question was closed?

Question

The question Why is bash history substitution still enabled by default? was closed at 2018-04-09-21:59:11Z. Ten minutes later, at 22:09:25Z a (perfectly reasonable) answer was posted by Jason Goemaat.

How was this possible? The question's timeline also shows the events in this order:

I first saw the answer when it appeared in the active questions list as "posted 7 seconds ago" to an "[on hold]" question. I thought it had been lucky to have barely made it in under the wire, but in fact the question had long been closed by then. I haven't seen this before and it seems either to be either a bug, or that I don't understand how question closure works.

Answer 1

As the meta posts linked by Jeff suggest, there's a window after the question has been closed where an answer that was already being composed can be submitted. 10 minutes isn't particularly egregious, I have seen 30 minutes, and a quick look at Data SE shows much greater gaps (apologies for the crappy SQL, I haven't touched SQL in ages):

• 177 minutes
• 157 minutes
• 151 minutes

This can happen when, for example, user composes an answer and:

• has a crappy network so the question closure is not reflected in their browser, and posts it (very likely on the phone app)
• puts their system to sleep and posts it soon after waking it