My comment isn't on the river action. I was just wondering what position you limped in with 7-7 as all you said was it folded to you. I've taken to folding (or sometimes raising) the smaller pairs in late-middle and LP because their biggest value is in flopping a set against a big hand, which isn't as likely if half the people have already folded. In addition you aren't as likely to get in a big multi way pot, the other kind of situation you like to be in.