Why return an object ElementMissing instead of throwing an ElementMissingException?

I am debugging an "Missing encoding data for: """ and I noticed something that maybe is wrong...

Should Header->get($name) return an object of ElementMissing instead of throwing something like ElementMissingException?

   /**
     * @param string $name
     *
     * @return Element|PDFObject
     */
    public function get($name)
    {
        if (\array_key_exists($name, $this->elements)) {
            return $this->resolveXRef($name);
        }

        return new ElementMissing();
    }

Start with the Header->get($name) method and its ElementMissing return path, then trace the missing-encoding case described in the report. Compare the current behavior with the proposed exception-based contract; done requires a decided, documented behavior and confirmation that the affected lookup path handles missing elements consistently.