A worker establishes a prima facie case of retaliation, if a causal connection exists between the worker's protected activity and an adverse employment action. The plaintiff optician's job description apparently required that he lift glass lenses and parts on and off polishing machines, and that he polish glass lenses. In 2007, a co-worker, Rick Thayer, allegedly complained that the plaintiff was not helping to clean the polishing weights. The plaintiff complained to a human resources manager that Thayer allegedly said that Blacks were lazy and that the plaintiff was trying to look White. Thayer denied that he issued any racist comments. The human resources manager cautioned Thayer against making future comments that could be interpreted as inappropriate and promised the plaintiff his workstation would be separated from Thayer's. Allegedly, the plaintiff hurt his neck when he lifted a heavy piece of equipment and also injured his hand when he climbed on an upside down bucket and fell. In May 2007, the plaintiff won 16 weeks of medical leave, after he herniated a disc in his neck. The plaintiff was scheduled to undergo surgery and decided to continue with physical therapy, because magnetic resonance imaging showed that he had made progress. In July 2008, months after his 16 weeks of medical leave expired, the plaintiff was discharged. The plaintiff sued the defendant employer, alleging hostile-work environment and retaliation. To prevail on hostile-work environment, a worker must establish a workplace permeated with discriminatory intimidation, ridicule and insult so severe or pervasive it alters the conditions of work. Isolated instances of racially hostile name calling usually do not alter conditions of employment. Thayer's alleged remarks were reprehensible but not threatening. The plaintiff admitted that he was not intimidated. The court found that the alleged remarks did not affect the plaintiff's job performance to his detriment, and it granted the defendants' motion for summary judgment on hostile-work environment claims. The plaintiff's retaliation claim survived. The plaintiff was discharged soon after e-mails were sent that discussed the plaintiff's prior discrimination complaints. "This type of 'smoking gun' evidence," wrote the court, "is sufficient to demonstrate pretext."