What does "indiscrete marriage" mean in the context of this sentence?

Does indiscrete make sense in the following sentence? Is this word used as synonym of indissoluble?

The instincts and conduct of the young man who aspires to the eminence of a dukedom, from which he seems hopefully removed by the precedence of several relatives and an indiscrete marriage which his mother made, are elegant and impeccable.

— The New York Times, Books (Alec Guinness Plays 8 Roles in 'Kind Hearts and Coronets," at Trans-Lux 60th Street).

Oxford Dictionaries, indiscrete: "not divided into distinct parts".

It seems to me this is more likely to be a misprint for indiscreet — lacking discretion; unwise.

IMDb has this for the plot of Kind Hearts and Coronets:

Louis Mazzini's mother belongs to the aristocratic family D'Ascoyne, but she ran away with an opera singer. Therefore, she and Louis were rejected by the D'Ascoynes. Once adult, Louis decides to avenges his mother and him, by becoming the next Duke of the family. Murdering every potential successor is clearly the safest way to achieve his goal...

...and I guess an opera singer was thought to be rather infra dig.

They've used the wrong word:

indiscreet: not discreet; imprudent or tactless

is the word they meant to use.