I agree with calling preflop. For 4bet I need the reads in these positions.
As played, I can imagine that he can play some top pairs this way - for example some possible 3bet bluffs like A5s it´s reasonable to x/b. Also with AK or AQ he can decide to check back given his hand is not so vulnarable and probably don´t have 3 streets of value so often. Also A on the river is bad card for bluff I guess. So I think x/f R is OK.
About leading T which Berezovaya suggest - personally I don´t like it. What we want to achieve by this play?