Rodrigo's loose pass in midfield resulted in Cristhian Stuani being played through on Jan Oblak's goal by Patrick Roberts, the goalkeeper tripping the Girona striker just inside the box.
Stuani beat Oblak from 12 yards out to move clear at the top of La Liga's scoring charts but Atleti scrambled a late equaliser thanks to a spectacular own goal by Jones Ramalho.
"In the normal line that we are used to, he takes risks because of his personality," Simeone told a post-match news conference.
"The balls can be lost and they took advantage of it very well. I liked the team a lot, in the first half we played the way we wanted.
"Girona are a very tough and complex team who are having a good time, with a goal to tie, win or lose.
"La Liga is barbaric, there are no simple rivals and that makes it appealing."
Ramalho diverted a volley into his own goal as part of a desperate attempt to stop Diego Costa from scoring, the Spain striker having brilliantly controlled a long pass from Angel Correa.
Costa was playing through the pain of a foot injury and Simeone hailed the forward's battling performance.
"It was the purest Costa," Simeone added. "He's making an effort, he left his soul in every move."
Atletico were without a trio of key defenders with Juanfran, Filipe Luis and captain Diego Godin all missing out due to injury.
And midfielder Koke hailed Atletico's character in coming from behind to earn a precious point, avoiding their first LaLiga loss since September 1.
"We played at a great level today," Koke said. "We were unlucky in front of goal and we have to congratulate the team for the effort. We have to continue working like this and the wins will come."