When warrior gets stunned or immobilized from different enemies at one time, the aura is stacking with itself (maybe because healing from second wind is target related), making possible to have 2, 3 or more 'second winds' on you and healing much more. Only one proc should be active at a time.
When you get few stuns from the same enemy, the Second Wind effect only renew, as it should be.
Could it be easily fixed by not relating a proc with enemy, that gave the effect, or just limiting it to one Second Wind aura at a time?