after all he called your raise from sb preflop. if he's got a T he probably has KT, QT, JT ot T9, then a bet is an absolute on the turn (3 additional outs to the 8 for openended str8 draw plus the fact that he already may have the best hand). AT or TT he would have reraised preflop I think. T8 and lower he would have fold preflop.