He said that Steven Defour's red card made things much more difficult but that in the end Porto were beaten by a slightly better side.
"If we'd scored that would have given us a lot of room for manoeuvre – it would have calmed things down," UEFA.com quotes Helton as saying.
"The fact that their first goal and the sending-off came in such quick succession made it very difficult for us to defeat Malaga, who are a good side.
"Looking back, had we secured a bigger margin in our favour in the first game when we were on top that would have helped. However, we lost to quality opponents with lots of experienced players who have won their spurs at other clubs - that's what makes them such a decent side."
Porto won the Europa League in 2003 and 2011 as well as the Champions League in 2004.