it could be either one...there is no way to tell..when you start getting into complexes , especially breeding back unto the parents..you can have plants that can have a wide range of expression from one parent to another ...i have seen this with Monsoon temptation, PEOY x SAnders Pride, as well as sandy crosses crossed back with sanderianum...basically, the seedlings that this pod came from could have a many plants that look like Lady Roth and Lady Isabel,
weel..yeah..i would go with the label,,because there is no way to make an educated guessTrue. But I have never seen a Lady Isabel that looked like that. But I have seen a couple of Lady Rothschild's which looked similar. Although I have seen Lady Rothschild's that looked totally different. The variation of complex hybrids as you say. If the label says Lady Rothschild than I see no reason to doubt it.