One fundamental tenant of this country's anti-discrimination laws is that an employee, whether in Rhode Island or elsewhere, has to feel free to report cases of discrimination when they see them. If they are afraid that doing so will cost them their jobs, then it is unlikely that discrimination will ever actually get reported or acted upon.
For this reason, laws protect those who report workplace discrimination from retaliation by their employer. What constitutes an activity that is "retaliation" is broad. It can include formal actions like getting fired or disciplined, and it can also include things that are less obvious like an unfavorable transfer or making changes to an employee's schedule.
Even things like formal warnings or additional supervision can constitute an "adverse action" and thus a potential sign that the employer is retaliating against an employee who stood for his o her own rights, or the rights of another, to have a workplace free of unlawful discrimination.
These rules do not mean that a person who reports discrimination or is involved an investigation of an employer gets a free pass on all workplace expectations, however. If, for example, an employer has a valid reason to discipline an employee and can show that it would have taken action even if the employee had not complained about discrimination, the employer's actions will generally be upheld.
If, on the other hand, the employer's true purpose was to send a message to the employee not to report the employer's discriminatory and illegal behavior, then any adverse action, no matter how small, is illegal. Those who feel they have been victims of retaliation have legal options that they can pursue under federal law.