I think the Atlas pilots were probably in the Teamsters union (yo' Vinnie, youse gotta problem wit dat?). Often these unusual missions are flown by management check airmen who may have a union seniority number but no active union representation.
Airbubba,
Dreamlifter/LCF flights are no longer particularly 'unusual' - they're up to about 100 flights per month (4 LCFs so almost daily per airplane, typical leg ~ 6 hours). They are busy supporting the 787 (10/month rate early next year)