This is the flip side of the in-order counter: it counts loopback replies that arrived in a different sequence than the LBMs that triggered them were sent, which typically means the return traffic took varying paths, for example across an ECMP or LAG bundle, or hit uneven queuing delay. Because out-of-order replies still count as successful responses, this counter distinguishes a path that is reachable but reordering from a true packet-loss problem, which matters when diagnosing services sensitive to jitter. A loopback burst where several replies land here instead of in the in-order counter is an early flag that a downstream LAG or multipath route may be splitting this traffic unevenly.