Hombre, sería bastante menos correcto hacerlo así:
Código:
FROM Claims, ClaimsFollowUp, Repricing
WHERE (Claims.ClaimID=ClaimsFollowUp.RepricingID AND Claims.ClaimID=Repricing.RepricingID)
or (Claims.ClaimID=ClaimsFollowUp.RepricingID AND Claims.ClaimID not in (Select RepricingID From Repricing)) or
ClaimID not in (Select RepricingID From claimsFollowUp) and ClaimID not in (Select RepricingID From Repricing))
De momento se me ocurre esto (no lo he probado, no tengo ya hoy tiempo), quizá te sirva como provisional.