Just curious, did you have any engineers/product owners telling you that you should probably not do this feature, especially not push so hard (doing stuff late on Friday that can easily wait for Monday, etc...) to get it out?
The tree of possible causes here looks really bad. Either no one spoke up, or someone did. If no one spoke up because no one knew this would be a problem, it means the team is completely unqualified. If no one spoke up but they did know this would be a problem, then it means people are afraid to speak out (my money is on this one). If people did speak out, then the right people with the right concerns aren't getting listened to.
It's one thing to do regular code deploys and there is no harm in doing it on fridays, if the code happens to be ready. If something goes bad, you rollback, which hopefully is automatic.
But, pushing features out the door is different than just deploying, so seems this is what happened. Then it doesn't matter what day you release your unfinished feature, it's gonna cause bad times.