The 5 year pregnancy and other religious methods of dealing with deviance

One of the recurrent issues with religious restrictions on sexuality is how to deal with sexual transgressions. If a married woman's husband away has been away for 12 months, and she gives birth, how does a religion address this? The rabbis of the Talmud 1500 years ago declared that the length of pregnancy was 9 months, but birth can sometimes be delayed by 3 months, resulting in a 12 month pregnancy (Yevamot 80b). Apparently Muslim authorities made similar declarations, saying that a pregnancy can last 2, 4, or even 5 years. Likewise, I've heard of writings that a first pregnancy can be only 3 months long and yield a full-grown baby.

The source in the linked article is decrying this unscientific thinking, but it seems like the best alternative in a religious society that denies a high prevalance of transgression. Everyone knows that pregnancies are 9 months long (+/-), and much less than this will result in a small infant and much more than this is impossible, but declaring that reality fits the moral order rather than admitting the frequency of immorality is definitely more humane than calling people out on transgressions and treating them poorly. Which the editorialist seems interested in doing:

from a moral perspective, how can I provide a jurisprudential loophole for a woman who was probably promiscuous after the death of her husband and then presented her baby, conceived in sin, as a baby of her dead husband by relying on the [notion] of a hidden pregnancy or on a fatwa issued by some [cleric] or religious school? This is what happened on December 14, 1927 at a shari'a court in Mecca. The qadi... ruled that the baby was conceived by the woman's dead husband who had died five years previously.

Obviously the best option is to recognize that it's normal for healthy people to have sex, sometimes when it's against their religion's rules, and to provide a structure so that the best outcomes can prevail: sex ed, contraception, reasonable expectations. When that's not an option, a 5 year pregnancy seems like a great alternative.