Chelsea appeared set to climb back into third spot until Suarez headed home an equaliser at the near post in the seventh minute of added time.
The goal denied Benitez victory on his return to Anfield and merely added to the controversy after Suarez appeared to bite Chelsea defender Branislav Ivanovic midway through the second half.
However, after the game Benitez wanted to focus on the injury-time allotted by referee Kevin Friend after saying he missed Suarez's bite.
"I thought we were talking about football and we have the game nearly won, and it's a surprise why there are six minutes," Benitez told Sky Sports. "We don't know.
"The rules are very clear. Sometimes it's three minutes if you make six substitutions, or sometimes it's four minutes, but six minutes is not easy to see in any game, and six minutes 45 seconds is even more difficult.
"If we analyse the last goal, it's something we can do nothing about except maybe defend a little bit better.
"But still, six minutes 45 seconds is something I don't think we will see in any other game."
Regarding the Suarez biting incident, Benitez said: "I didn't see anything, I was concentrating on the game. I didn't see any incident."