Why didn't he just stay with Foss then?
He finished together with Knox and Serry btw, they did not give up on him in stage 4...
Almeida (as all other riders...) is human and, on that particular stage and based on what was happening inside his own team, was mentally all over the place....
He obviously is not the best rider in world but one thing he clearly is is a fighter, he never quits, and the way he ended that stage (the face, the will...) clearly showed us he was totally drained mentally and clearly not caring how much time he would lose....
On a normal stage he would have stayed with Foss and lost maybe 1:30 minutes... on that particular day it was a mess....
Regarding Knox and Serry staying with him... well...., I guess you could also say that today both of them stayed with Remco and, as you can see, the help was invaluable....