The Eighteenth Amendment says hello.
Preventing the introduction of subtle bugs when making changes to a complex system is hard, even disregarding intent. I'd say it's easier to catch deliberately-malicious patches, because easy-to-predict failures are the easiest to catch.
The thirteenth amendment, while intended to abolish slavery, actually rendered state-sanctioned slavery explicitly constitutional (albeit, with extra steps); e.g. the Black Codes in certain states prohibited “vagrancy”, which (afaik) basically let them enslave anyone they could get a jury to agree wasn't “contributing to society” via “gainful employment”. This lead to the fourteenth amendment trying to patch this issue – not by forbidding slavery as punishment for a crime, but by requiring “equal protection”: in essence, states couldn't make laws that only applied to certain people.
I don't have any examples of exploitable issues being deliberately introduced to legislation, because generally, people in a position to introduce them don't have to be subtle about it. Perhaps the 11th Congress of the Russian Communist Party's creation of the position of General Secretary was an example, but I don't know if we know what happened there.
Before the thirteenth amendment to the US constitution, §4.2.3 permitted slavery and, arguably, implicitly required its enforcement even by states that outlawed slavery. That might count, seeing as many drafters were anti-slavery, and did not expect this clause to allow the 19th-century resurgence of slavery-powered plantations; whereas other drafters were pro-slavery, and presumably insisted upon this clause's inclusion.
Patch 3
First email: Thu, 20 Aug 2020 22:44:57 -0500 (Fri, 21 Aug 2020 03:44:57 UTC)
First reply: Fri, 21 Aug 2020 11:14:49 +0300 (Fri, 21 Aug 2020 08:14:49 UTC)
https://lore.kernel.org/lkml/20200821034458.22472-1-acostag.ubuntu@gmail.com
This patch was quickly recognized by a reviewer to be incorrect, and the
reviewer offered up possible changes that the submitter could make in
order to turn it into a correct change. These suggestions were ignored
by the submitter and no further changes were submitted in this area.
The maintainer was attempting to mentor an obviously junior contributor,
taking time to teach the developer what the proper thing to do here
would be, and what is needed in order to have them create a
contribution that would be acceptable. The contributor knew that the
patch was bad, showing that the researchers were willing to waste the
resource that is in shortest supply in our community: the time of
reviewers and maintainers. Having this waste of an "effort of someone
trying to teach another" be created by an educational institution was
especially hurtful to the community and caused many of the bad feelings
on the community's side, further amplified by not having any idea which
patches out of the hundreds sent by UMN or from new contributors using
gmail accounts might be intentionally bad.
[…]
Summary of "Hypocrite Commits" patch attempts
All patch submissions that were invalid were caught, or ignored, by the
Linux kernel developers and maintainers. Our patch-review processes
worked as intended when confronted with these malicious patches.
As you can see, the time that was wasted was especially valuable, and the research did not demonstrate any such thing.