I don't know the circumstances you mention, but in many cases where bad weather occurs, then aircraft may not have been able to fly as planned and they end up missing sectors and are therefore in the wrong place. EZ don't have contingency plans if their airplanes go tech or end up so late that they can't make a particular sector. In summer they try and latch on very late night flights (where the airports allow this with nor curfew) or they just cancel due to economics (but they're not going to tell you that...).