I don't want to confuse anyone. I'm just really interested in why Marcus thinks that "Это случилось пять минут восьмого" is a normal phrase. For me it sounds just completely wrong, I've never heard anybody speaking like that in my life. Although, the в preposition is really quick there and therefore might went unnoticed, as for now it's the only possible explanation why Marcus thinks like that.
Also:
Да, это случилось пять минут назад, двадцать минут второго.
Even this phrase looks incorrect to me, in my opinion it should be:
Да, это случилось пять минут назад в двадцать минут второго
It's just when you say that something happens, happened at a particular "watch" time, you have to use в before the "watch time" expression.
Also, given the Marcus logic we can easily deduce that it should be okay to say:
Это случилось пять instead of
Это случилось в пять.
Seriously, what the hell is
Это случилось пять?