Yeah I mean he can have flushes, FH's, Ax, etc. for value. Even your read is correct that he 1/2 pots for value, he can still have better hands that are bluffing here. 65s is only 4 combos.
Ok, so i have a big sample on this guy.He would NEVER shove a flush, he always value bets 1/3 or half pot on the river with strong made hands.Secondly i watched him play str8 draws, vs me and others, and he always plays them the same:Calls flop, calls turn, bluffs river if misses-or-Calls flop, raises the turn if he hits.Fd`s and top pairs, he always raises on the flop.
none of the above justifies the call.
65s is pretty much the only group of hands you beat.
What about: (35s, 68s, 58s, 63s that this guy is not folding to a 3b)
Maybe it`s spew in the long run i dunno, prolly is, but i make these calls once in 5k hands.Against this guy i was almost sure i had the best hand due to notes and reads.Against an unkown, i would fold 100% of the time.