"was commented" is correct and usable in written English.
You can use it when you are reporting what someone else has said. For example, "His opinion on the matter was commented on by several observers."
The linearity of such curves for non-Newtonian honey was commented on in ref. (2).
This was commented upon by the noted British diarist and country-house historian James Lees-Milne.
Previous published paper "Inhibiting the regeneration of N-nitrosodimethylamine (NDMA) in drinking water by UV photolysis combined with ozonation" by our research group, was commented by Dr. Xiao.
"The fragility happened over a long time," was commented on by many visiting committees, ultimately leading to a "serious crisis" two years ago, he said.
What is known is that the Boumsong deal was so odd that it was commented upon by every observer and plenty of Newcastle fans at the time.
When Terry Wogan retired from his breakfast show last month, it was commented that he had been offered the chance to read his obituaries in advance.
"Fifty years of pride down the drain as far as I am concerned," he intoned in a segment that was commented on for weeks.
This was commented upon by an investigation and report by the National Audit Office which has been ignored completely in this report.
It was commented at the time that the same might happen with the Booker were it not for the precaution of excluding American novelists.
It took a little while to establish that she was looking at a sofa under the lights, though its color was commented on at once.
It was commented upon that this was entirely in line with the ordered nature of his life and, further, that it reflected the perfection of his experimental procedures.
