4 hours ago (at 15:53:08UTC today), I closed this question over on CodeGolf.SE. We've discovered before that it's possible to answer a few minutes "under the line" due to caching before, simply by not refreshing the page. For example, this answer was posted at 15:59:08UTC.
if the closure check is client-side could one theoretically just disable it an post an answer to an already-closed challenge? and if it isn't cilent-side, how is Neil able to do that if it should be closed server-side already o.O
A few minutes of caching isn't much of an issue, hours of caching potentially is.
Is this a problem?