However, by tweeting it and referencing the tweet, you have created a breadcrumb trail for someone who wants to investigate further. Providing sources isn't just for 'factual proof', it's also for investigation - if someone is interested in a topic, they can go to referenced sources.
It's the whole point of references in academic papers: "To know more, start here".
It can only happen if somehow Wikipedia's citation process is intentionally circumvented, and if no other user ever reads the article to fix the error. If you read Wikipedia's citation guidelines, that goes against a couple of very basic rules.
Regardless of what the wikipedia guidelines might say, it happened.