Strange behaviour of dot operator with String's indexOf method.

[yonatan]

-> (let [s "abcd" 
         index-of (. s indexOf)]
     (index-of "c"))
5

-> (let [s "abcd" 
         index-of (get-property s "indexOf")]
     (index-of "c"))
2

-> (let [s "abcd"] 
     (= (. s indexOf) (get-property s "indexOf")))
false