

It is also interesting to note that there is speculation among historians that Da Vinci may have deliberately included errors in the designs of his war machines, as he was probably more of a pacifist.
This is mentioned, for example, in this article on the design of the Da Vinci tank:
Some scholars argue that Leonardo, a known pacifist, may have deliberately included this flaw to prevent his design from being used for warfare. Others, however, believe it could have been an oversight.
This article was just one not pay walled piece I found right away - I figured I’d at least mention some kind of source. I’m sure there’s much more information on this to be found elsewhere.