Svilar conceded twice in the Champions League defeat, including an attributed own goal.
"Mixed feelings, of course – a lot of emotions in twenty minutes but I think I couldn't do anything about it, it is luck," he told UEFA.com.
"There was nothing I could do about it but it's still an own goal.
"I enjoyed it a lot, I tried to enjoy the whole game, at my age it's something special. Great fans, great Benfica fans, they were so good. But a pity we couldn't take the three points."
On United keeper David de Gea, Svilar added: "We played really well, we had a lot of chances but an excellent [David] De Gea as well, so well done to him. As a team, we played really well and I hope we will continue like this in the league and the Champions League as well."