Escaping special keywords in PHQL

In MySQL I can just do something like the following:

SELECT * FROM treelist ORDER BY `left` ASC;

but if I try to do the following in Phalcon I get an error:

TreeList::find(['order' => '`left` ASC']);

What's the proper way to escape special keywords like "left" and "right" in PHQL?

Also, some unrelated questions:

• Is Model->afterFetch() broken in 2.0.7 or am I doing something wrong? I tried code which looks similar to the following but it seems afterFetch() wasn't even called (beforeSave() works fine though).

class Robots extends Model
{
    public $id;

    public $part_id;

    public function afterFetch()
    {
        if (empty($this->part_id))
            $this->part_id = -1;
    }
}

print_r(Robots::find()->toArray());

• What's the best way to strip tags from all fields before saving model? Should I do something like the following or is there a better way?

    public function beforeSave()
    {
        $filter = new Filter();
        $fields = $this->columnMap();
        foreach($fields as $field)
            $this->{$field} = $filter->sanitize($this->{$field}, "striptags");
    }