Adam Davies, leader of the orang-pendek expedition, posted a response on Cryptomundo to the various questions he received in that forum. Read the whole text by following the title link. Here I'll just quote his response to my question about identity:
" Matt Billie asked a very good question as to whether it could have been a Lars Gibbon. I am used to seeing Gibbons in the jungle, and Sahar is a really experienced guide. I am certain he would not mistake an Orang-Pendek for a Gibbon, and his astonished reaction compounds that view. The physical descriptions by both eyewitnesses do not match Gibbon. "