Cahill said: "Sylvain's been our player of the season - that's the only way I can put it.
"One mistake doesn't sum up his season.
"He's been immense and, as a team, we possibly should've still been out there playing extra-time.
"We shouldn't have conceded the second goal, giving the free-kick away and defending the way we did.
"As for Sylvain, he's a top player and it happens in football. We've all been there at one stage in our career."