It is possible to configure static routes in Neutron Routers whose nexthop is an InterVpnLink endpoint.
InterVpnLink engine is programmed to install the needed flows in LFib and Fib tables when this happens, however, so far it doesn't check if there are already static routes pointing to one of the InterVpnLink's endpoints when it is created.

This corner case happens when an InterVpnLink is removed (by mistake or whatever) and then re-created again with the same endpoint Ips. When an InterVpnLink is removed, it removes all flows (and fib entries) related to the InterVpnLink, but it does not remove (by requirement) the static routes that may have been manually configured by an operator on a Neutron Router.