A "tip" can refer to a tip off, which is a small piece of information to point someone in a certain direction. In this case, a witness tipped off the police as to where the suspect was.

However, a "tip" can also refer to an extra, voluntary payment in addition to the mandatory charge. Usually people give tips as a way of being polite and letting a service worker know that their performance was satisfactory.

Since the person who was arrested was in a McDonalds, and since a tip off lead to their arrest, I presented a humorous misinterpretation of the situation where tipping a McDonalds employee lead to the arrest, and I advocated avoiding tips in all circumstances.