I once accidentally gave my claude "powershell" permissions in one session, and after that any time it found it was blocked from using a tool, e.g. git, it would write a powershell script that did the same thing and execute the script to work around the blocked permission.
Obviously no sane system would have "powershell" in a generic allow-list, but you could imagine some discrepancy in allowed levels between tools which can be worked around with the techniques on this page.