It turns out that this problem is solved using the solution [here][1].

The answer is that `FindRoots` needs to have the option `Evaluated->False` to ensure that the nested `RootSearch` is evaluated before the FindRoots[expr] takes place.


  [1]: https://mathematica.stackexchange.com/questions/11297/how-can-i-get-mathematica-to-allow-me-to-apply-findroot-to-an-expression-that-co