I'm arguing that you don't know either way.
And how do you know they could have gotten him in the 5th or 6th round? What information from general managers around the NFL do you possess that qualifies you to make that claim? For all you know, the Seahawks might have been looking to pick him at #123. I'm sure if Ted thought he could get him later, then he would have drafted him later. Most likely, he had knowledge that some teams that were coming up soon were fairly high on him and he pulled the trigger because there is something very specific about Tretter that he liked.
I'm not sure you're aware of this or not, but NFL general managers don't get their scouting information from the Walter Football website, or Bleacher Report, or NFLDraftGuru.com, or DraftTek.com. And they certainly don't get it from idiots like Mel Kiper either.
You can spend hundreds of hours scouring every mock draft on the Internet and memorizing every scouting report on cbssports.com, but in the end, you still don't know half of what the guys who actually do the drafting know.
There's no need to be insulting with your tone (re: GMs getting their information from Bleacher Report, etc.). I possess average to above-average intelligence and I think my outsider's understanding of the draft process isn't significantly better or worse than your own.
Nobody, including the guys that actually do the drafting, know anything with certainty during the draft. It's a cloak and dagger environment of incomplete and misinformation. What's actually relevant to my criticism of this pick are two items: (1) the likelihood that Tretter would be available later and (2) whether another prospect of similar profile could be substituted for him later. You can gather my view with regard to these items based on my posts above criticizing the value of this pick.
If you disagree and view Tretter as a solid value where he was chosen, then it stands to reason you believe (1) that Tretter was unlikely to be available later in the draft and (2) Tretter is a special talent that could not be substituted by other available guard prospects. Otherwise you're losing out on value by taking a player earlier than necessary to secure him, which was the thrust of my original criticism.
Tretter measured well, but not exceptionally, at the combine and I have a difficult time evaluating his abilities against Ivy League competition. Perhaps Ted sees something I don't. It doesn't look like he'll be ready to contribute right away next year but we'll see what happens. Tretter might become a ten-year starter for us in the future. Nonetheless, the value still doesn't seem right using the above criteria, but that's just me.
Either way, America's a great place: people can disagree with one another and still coexist.