The "fact" is they were employed as scabs on fixed term contracts for the very purpose of working should long haul crew take industrial action. So what if they are now in LHR and come back to a permanent position in long haul (if its still here in 2 years) the fact of the matter is they are/were a scab.
Maybe they are competent but the only FACTUAL information on the fixed term crew now up in LHR is the above.