Or they just hire enough staff to run the business in the first place. Something that used to just be how you operated a business. If the business wants to gamble on regularly operating without enough employees to cover multiple sick calls then they need to deal with the results of that decision.
Pull from other locations to cover, or God forbid, a manager actually covers a shift, or just close the location for a day if they cannot cover it. You know, what every business that operates with employees deals with.
You're making excuses and trying to find a justification for a fucking disgraceful, greedy choice by the owner of this business.