Complementizer development in Latin

As most Latin folks know, oratio obliqua doesn't have a complementizer in classical Latin.

1. Puto    Dalleca a   Doctore     vici.
    I.think Daleks   by the.Doctor to.be.defeated
    I think that the Daleks are defeated by the Doctor.

First, because Doctor Who. Second, there's no complementizer, which is to say that there's no word that corresponds to "that" in English. It's not a big deal. We certainly can skip using the complementizer in English.

2. I think the Daleks are defeated by the Doctor.

Completely grammatical. We might even be able to parallel the Latin syntax and switch to an infinitive.

3. I think the Daleks to be defeated by the Doctor.

Though some native English speakers may feel I'm pushing the bounds of acceptable on that one. Anyway, the reason I bring this up is that at some point Latin picks up a complementizer. It presses quod, which is a conjunction meaning because, into service as the complementizer. So our first sentence might become something like this if it were to show up in the Vulgate.

4. Puto   quod  Dalleca a   Doctore     vicuntur.    I.think that    Daleks   by the.Doctor they.are.defeated
    I think that the Daleks are defeated by the Doctor.

And that's no small matter. Aside from adding the complementizer quod, we made two other shifts. One is invisible, because I couldn't resist the notion of the Daleks in Latin. The noun is neuter so we don't see it shift from accusative in 1 to nominative in 4, so you'll just have to trust me that it works that way. The other thing I did was to shift vici from an non-conjugated infinitive to a standard conjugated verb, vicuntur.

The reason I bring it up is because in my preparation of de Senectute for publication as a reader for intermediate students, I've noticed that quod seems to behave oddly. It's like you could interpret it as either because or that. (And if I think of it I'll dig up an example of this, but not today.)