Also consider that it may very well have been an overtightened chain. If you really pull it tight at the loosest spot in the crank's rotation (they aren't perfectly round) then it can bind at the tightest spot. However, if this is the case, it is fairly obvious, as it only binds or gets really hard to move at one spot in the rotation. Also, you can just put your finger on the chain and see how tight it is yourself.
Although this may be a moot point now.