The African national were set to progress to the knockout stages for the first time in their history, with the closing Group C match against Greece all square at 1-1 in stoppage time.
But Georgios Samaras kept his cool to net a last-gasp penalty after the Celtic forward was adjudged to have been fouled by Giovanni Sio.
Coach Sabri Lamouchi subsequently handed in his resignation after becoming the latest boss to fail to make a talented squad fire effectively on the world stage.
"Still I am very disappointed," Liverpool defender Toure told Linfodrome.it.
"I think we could manage our game, but we we very naive collectively. We were not smart and we all are sinking.
"I think I could have done better, the team could have done better, but we were very naive."
On Lamouchi's departure, Toure added: "I do not want to comment on the resignation of Sabri Lamouchi.
"This is a coach who has decided his future and he does what he wants.
"But I think it's time (for) the players and the team to regroup. At this time, I'm really disappointed."
‘He instantly popped into our ratings as one of the best U21 midfielders in Europe. The impressive thing is Slot has made him into more of a no.6' Inside Ryan Gravenberch's transformation at Liverpool
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
