Offer was extended a week after the panel interview and compensation was significantly below (15%) what was verbally agreed upon by HR during the interview process. Attempted negotiation to slightly higher salary (still below agreed upon amount) only for them to rescind the offer from the first sign of salary negotiation. Remarkably unprofessional act I have ever seen in my career. In this case, it would be the hiring manager or HR that called for the rescinded offer. However maybe the case it is a very bad look for the company.