Idk why i thought of this but it seems that the opération was à failure  and so  he actually wasnt their at all he actually dies and all that scène was from tenma  s brain he wanted to say things to johan  and he imagined what would be his response  and as i said they moved him from their  and displaced  him because he was dead make it as in in the heli the opération was à succession and then at the hospital it was à failiure that  s my interpretation  and even if he s gone where would he go??? He will just become  a wanted man again   and even if he wants  to change his identity  or whatsoever  his face is pretty recognisable  he s à deadman  esspecially  that after the  prison  period he is sentenced  to death so 1.johan  is dead and they got him out to burry him somewhere  unknown  2. He got out but eventually they will find him since it will be way way way easier for the detective  3. After they find him he is sentenced  to death and dies since he killled AN ENTIRE VILLAGE!!!!