The verb 'help' takes to-infinitives and bare infinitives but bare infinitives are said to be the most common in casual text; as also used in this example sentence.
A casual remark can hurt someone.
Polite language, in a sense, spoils a casual atmosphere.
You wouldn't be so casual about it if you were directly involved.
Her coat was too casual for the occasion.
They are collecting information by casual methods.
It was a casual meeting.
Up to now we've been taking a casual relaxed attitude toward our relationship but I want to start looking at us more critically.
He was an amiable fellow, but had a certain reserve that he would not let you casually trespass upon.
He picked up the newspaper and glanced casually over the front page.
I took a casual look at the magazine.
The fact is apparent to the most casual observer.
That topic is too intimate to share with casual acquaintances.