My problem is that, maybe, 5% of the time the module does not register a response, but the server registers the request as if nothing wrong had ever happened.

Not possible

Either one or both would register a partial response

Would it really be that easy?

Sure, why not :) Its that easy if it does what you expect :)

Or is there some consequence I'm overlooking?

Sure, why not :) If you add tests, and document thoroughly, you will run into it, if it exists :)