Aldrich recalled his terrible experience on the ancient land bridge and bit his lips. He was indeed suspicious and a little apprehensive regarding the blind priestess.
The main reason was how easily she disolved the situation and how she made him lower his guard towards her.
Even that was only because he knew he logically should not trust her. Not because he actually felt malice or ill intentions from her.
His senses was only a feeling and it could be wrong which is why Aldrich used a logical approach to weight her in his mind.
Even then it was hard, considering that she saved his life and her general impression, trustworthy and kind that was the kind of feeling she gave off.
But to Aldrich the thought that she might be tbe oracle simply never occurred to him. In fact if he was asked he would think that banshee was more likely to be the oracle.