Followers of Umar have removed every evidence which proves that folding hands was ordered by him and claimed that it was done by the Prophet but they failed in presenting any authentic Hadeeth to support their claim. Muslims of Madina used to pray without folding their hands. Malik bin Anas the founder of Sunni Maliki sect clearly mentioned that the Salaah should be with opening hands and not folding them.The narration in Bukhari on this subject is from Sahl ibn Sa'd never said that the Prophet ever folded his hands in Salaah but states that people were been ordered to fold their hands. The narration was made after the order of Umar to fold hands in Salaah. 

No one knows the real Sunnah of the Prophet (SAWS) more than Ameerul Mo'mineen Ali (AS) who was against folding the hands and clearly ordering Muslims not to fold their hands in Salaah because it is a practise of the Zoroastrian and Jews.Wassalam