An official report of Human Rights Watch refers to "rumors" that Hashd killed ISIS prisoners

There no questions that HRW and other Western human rights organizations adhere to different standards when it comes to enemies of Israel and US.  Similarly, they refer to much stricter and higher standards of evidence when it comes to crimes and human rights violations by allies of Israel and US.  This official report of HRW refers to "rumors" regarding killings by Hashd in Iraq.  Do you think that this organization would ever dare to refer to rumors when it comes to war crimes by Israel or its allies in the region?