Are there any particular situations, where a triggered update might not be able to prevent a routing loop?
Triggered updates in RIP are designed to prevent routing loops. There are cases where triggered updates will not be enough to prevent routing loops, but those are due to bad network design. One example is if you disable split horizon using the
no ip split-horizon rule under the router configuration. There are legitimate times when this should be done, but if it is not done carefully and under the correct circumstances, routing loops can occur that cannot be stopped by triggered updates.
I hope this has been helpful!