It was marginally a bad and fishy, but very common call. SPR of 5 would not favor small pocket pairs. Even if you were open raising a wide range, 55 is not a favorite, and plays poorly without flopping a set. The only thing opponent had was position, and misinformation regarding the value of 55. Calls like this are made because people think they can win alot if the hit their set. Few players, especially live, understand the math behind no limit poker. really. They all think they do. Even though you may have lost a medium size pot, you can be sure the call is losing your opponent money. It's cold comfort, but that is poker.