The correct interpretation of that verse is found by reading the whole passage. First, different cases of adultery are considered, the penalty for which was death.
22:22 is the case of a man and woman who are both guilty of adultery, and both are put to death
22:23-24 applies the same penalty to man and woman, even if the woman is merely betrothed; this verse considers that both consented to the adultery.
22:25-27 considers the case of an unmarried and unbetrothed woman who is raped; the rapist is put to death.
22:28-29 considers the case of an unmarried and unbetrothed woman who has consensual sex outside of marriage; this case is not adultery or rape. This consent is implied by the context of the previous verses, since, if it were a case of rape, the man would be put to death.
The man pays a dowry to the father, as was the custom of the time. And he cannot divorce her, even though the Israelites permitted divorce in many cases, because sex before marriage is a sin. The young woman is not punished because he is considered to have the greater guilt, since the man tended in that culture (and in many cultures today) to be the one who pursued the woman, rather than vice versa.
This is a good, succinct answer. The penalty for nonconsensual sex (rape) in Deuteronomy, at that place and time, was death.
The proof-text cited on Facebook has to be considered in the context of the entire passage, which lists penalties for different circumstances. (As a priest I knew used to say when someone cited an out-of-context proof-text, “I’m pretty sure God wants you to read the lines above and below that one…”)
We should also look at the language used in the translation cited. “Rape” is not used in all translations for this passade, nor is it the correct one in context.
To go further into this (at probably greater length than is necessary):
Deuteronomy 22:28-29 “If a man meets a virgin who is not betrothed, and seizes her and lies with her, and they are found, then the man who lay with her shall give to the father of the young woman fifty shekels of silver, and she shall be his wife, because he has violated her. He may not divorce her all his days."
The choice of words of “and they are found” indicates that this refers to a consensual act. Thus, “seizes” used in this context seems to imply a lustful or passionate act, but not a non-consensual one, as the term “ravished” in English implies a lustful act but not necessarily a non-consensual act of rape. This sounds more like a description of a shotgun marriage, Israelite-style. The violation involved was loss of her virginity, which would make her unmarriageable in the eyes of their people, so the seducer would have to marry her. He would also forever lose his ability to divorce her, no matter what she did in the future.
Many English translations of this passage do not carry a connotation of rape: Douay Rheims doesn’t: “If a man find a damsel that is a virgin, who is not espoused, and taking her, lie with her, and the matter come to judgment.”
The term for taking or seize in this passage in the original Hebrew is a combination of two words, TAPHAS (to catch, handle, lay hold, take hold of, seize, wield) and SHAKAB (to lie down, to bed, to rest).
That this law does NOT apply to rape is shown if you read it in the context of the earlier passage. The actual penalty for forcible rape is quite reasonable (execution of the offender, with no penalty to the victim) and is probably far more compassionate than existed in the middle east then, or in many middle eastern countries now, where loss of virginity for a girl even by rape can result in the execution of the woman by her own family for being “dishonored,”
