The article related to this post mentions that in Rome, working out monetary compensation for the life of a family member was a common practice. It's not a uniquely germanic-in-origin practice.
Whereas in the barbarian kingdoms and later on, all murders were initially a private matter and people retained the right to kill someone back (not necessarily the killer) unless they opted for the compensation. If this specific case happened after the fall of the empire, probably the father would have just killed the husband back instead of seeking government involvement. And probably the husband's family would have not thought it fair and either seek compensation or kill another member of the wife's family.
Either way, I'm glad things have changed since then!