In a strongly worded letter to Pillay, Sri Lankan government took exception to the "inappropriate tenor" of her language.
A top external affairs ministry official, Kshenuka Seneviratne, rejected Pillay's January 18 statement, dubbing it as "deviation from established procedure amounting to blatant interference in an issue of a sovereign country".
The impeachment of 54-year-old Shirani Bandaranayake, the former chief justice, was carried out by following due procedure as set out in the Constitution, he said.
"The content of your statement sadly demonstrates that neither you nor your office has the understanding of the provision of Sri Lanka's Constitution," Seneviratne said in the letter.
Bandaranayake was sacked after a parliamentry panel found her guilty on three charges of financial impropriety based on non-declaration of assets and conflict of interest in a case involving a failed investment company.
Critics say the chief justice did not get a fair trial and the case against her is an attempt by the government to stifle the judiciary's independence.