The concept of discipline in work place includes disciplinary control over employees. This is accomplished through a set of procedure called disciplinary proceeding or disciplinary action comprising of several stages such as calling for explanation by issuing a show-cause notice, framing of charges of misconduct through charge-memo, conduct of domestic enquiry, issue of a second show-cause notice on the conclusion of the charges having been proved and the final orders. All these things are based on the Principles of Natural Justice. But, skipping a step or two is a matter of expediency based on the gravity of the misconduct and the reasonableness of the circumstances leading to the final decision. So the opinion of your Senior is also correct. But in a clear-cut case of a serious misconduct, skipping the first show-cause notice can not be a flaw.