Kate said there were so many errors they made new ststements with CRG which were sent to the. PJ
Yes. Why they decided on 13th May that parts of the statements they had made might have been lost in translation is not explained. Nor do these new statements appear in the PJ files, so there's no evidence of what they said or that the PJ received them. Even those statements. taken and recorded in English, weren't correct according to Kate. Unless, of course her memory of what she meant to say is the problem rather than the records.
Kate's references to 'lost in translation' have only one possible conclusion imo, which is that she is suggesting that the interpreters didn't do their jobs properly. In fact she's naming Natalia Carvalho Ferreira de Almeida and Alice Dias Homem de Gouveia Avakoff.
How do you detect that something has been lost in translation? In the McCann's situation they could only compare what they meant to say with what the interpreters read back to them. If the two accounts didn't match the time to mention it was then, rather than saying nothing and signing that it was accurate.