Naturally occurring anti-Bredt bonds have been known for a long time.
From a good 2014 review:
“ Lastly, we feel that Julius Bredt himself probably would never have imagined his legacy would continue into modernity, especially as he was already aware that violations of the rule were on the horizon. Nevertheless, the occurrence in nature of architecturally beautiful and biologically active candidates, unearthed by the isolation chemist, suggest that the field will continue to develop attracting the attention of biologists and chemists alike.”
Naturally Occurring Anti-Bredt and Bridgehead Olefinic Systems
Jeffrey Y. W. Mak, Rebecca H. Pouwer and Craig M. Williams*