Runtime verification involves checking whether an execution trace produced by a running system satisfies a specification. However, a simple ‘yes’ or ‘no’ answer may not be sufficient; often we need to understand why a violation occurs. This paper considers how computing the edit-distance between a trace and a specification can explain violations by suggesting correcting edits to the trace. By including information about the code location producing events in the trace, this method can highlight sources of bugs and suggest potential fixes.