[jleader]

Every place I've ever worked where I had any visibility into hiring, at the start of the search the company makes a decision as to who they want to deal with: hire an inside recruiter, retain a single outside recruiter (or several), or accept referrals from all outside recruiters. Once they've made that decision, when a recruiter sends them a resume, either the recruiter they're willing to work with and whose fee they've already decided they're willing to pay, or it isn't. In the latter case, they respond saying "we've got our own recruiting arrangements, thanks" and toss the resume. In that case, if the same resume comes in through a different channel later, they're under no obligation to the recruiter, and they'd be perfectly happy to hire you.

I suppose if they were working with a recruiter, and later ended the relationship, that could cause the problem you describe, but I haven't seen it happen (as a job seeker, a member of many interview panels, and as a hiring manager a couple times).

In theory, the recruiter isn't supposed to send resumes without the job seeker's approval, which means that when they do so, they've probably broken any agreement they have with the hiring company, so the company probably isn't bound by that agreement any longer. Whether you'd be able to convince the hiring company to take the risk of a lawsuit (that they'd presumably win) is another question, of course.