The Basque side's goal came from a Araujo mistake that Kike Garcia made the most of.
The centre-back spoke about his slip-up afterwards and took full responsibility.
"It's a shame that we didn't take the three points," he said in a post-match interview.
"It was a very quick piece of play and I didn't see that their striker was so close to me.
"We play a high line, so losing the ball where I did is dangerous. But, we do take that risk.
"You can't make such errors and I take responsibility."