Watched the game today and I mostly agree with your analysis, Om. Big surprise there, I know. I did have a couple of thoughts as sort of an addition/possible explanation.
On the third attempt (1st-10, Wash 38) I am thinking Campbell read straight man coverage with the DBs all up on the line in press position like they were. At the snap, the DB on ARE in the slot gave him a slight bump and released him to the inside then dropped into what appeared to this layman to be more of a zone and which put him right in the passing lane Campbell was trying to use to go to Thomas. If he was reading some sort of blitz at the same time, he might have been using a hot read to Thomas but that is just me thinking (might also be making excuses for a QB I would really like to see succeed).
On the fourth attempt (3rd-6, Was 42) I rather like what Campbell did. I think had that been any one of the top 4 guys on the roster at WR they come down with it and if it had been Kelly or Thomas there was a real chance for serious yards after the catch due to the height difference. I am guessing you got some views on the live show that those of us seeing it on the NFL version a day later didn't get cause I could not see any of Cooley's position as described by you at all so your evaluation could certainly be better than mine.
Over all I was pleased with the pass protection while the starters were in the game. Rinehart did much better at it then I had expected although he got whipped on at least the first running play of the game. This showing by him has me breathing a bit easier about the backup situation for Thomas at least. Still holding out judgment on the RT position, although Williams was better than expected against Baltimore's seconds and thirds. Really scary is the thought of losing Samuels...