Bearfoil
There has been no evidence presented by the BEA that indicates any attempt by ATLANTICO to contact AF447 post the three non answered calls at 0136. That means there was no attempt to establish its position prior to transfer at TASIL, and no mention has been made that ATLANTICO even advised DAKAR that they even tried.
To put it bluntly, once DAKAR advised ATLANTICO that they had not received a flight plan for AF447, and ATLANTICO had passed the essential plan details on to DAKAR at 0146, ATLANTICO "let the aircraft go".
Radio procedure and etiquette had been performed normally up to 0136, but as pointed out in the last paragraph, it then "went to hell in a handcart".
mm43