First, note the loaded word “admit,” used to prejudice the argument. What we “admit” to, it’s implied, has something bad about it. (“He admitted to being a member of the Hare Krishna cult.”) The neutral word is “say.”
Apart from that: The editors also admit that their service during Śrīla Prabhupāda’s lifetime was to edit his books and that he never asked them to stop.
Śrīla Prabhupāda knew there were mistakes in his books, and he wanted those mistakes fixed. Consider this excerpt from a class in Hawaii (January 1, 1974):
Prabhupada [interrupts the word-for-word reading]: Hm? Purusadaih—by men? Purusadaih. . . purusadaih means raksasa, the cannibals. So there has been. . . ‘Cannibals,’ it should be. You [Pradyumna, presumably] can have a notebook. . . Whenever there is some discrepancy, you note in the next [that is, for the next printing]. Purusadaih means ‘by the cannibals, raksasas.’ [word-for-word reading continues]
In September of 1972 Pradyumna wrote to Jayadvaita:
Prabhupada said that if there is one mistake in one book, then you spoil the whole book. Murder the whole book. So also besides Sanskrit errors, there have been many, many English errors also, which are very obvious. . . , so Prabhupada has been emphasizing lately about the great need for making our books free from errors. “What's done has been done” [Śrīla Prabhupāda said], but now we should try to do two things: make sure that errors like these won't occur again, and start a listing of past mistakes in each book so that we can correct them when they are reprinted.
The BBT editors admit to doing their best to continue following these instructions.