The disgraced former "Empire" actor claimed he received a text from Lemon tipping him off that the Chicago police didn't trust his account of the events that night, in which Smollett claimed that two Trump supporters assaulted him.
That information was reportedly key in his decision to refuse to hand over his cell phone to investigators at the time, the New York Post added.
Several media outlets reported on the revelation as notable in the trial. Yet during CNN's Monday night coverage of the trial, neither Lemon nor network reporter Omar Jimenez said so much as a single word about it.
Lemon, who is also gay, previously acknowledged that he texted Smollett "every day" following the alleged attack to check in on the former actor and see how he was doing. But he never mentioned that those personal messages involved sharing important information about the case.
Smollett is accused of staging the attack to boost his acting career and is now facing six counts of felony disorderly conduct.
Why does it matter?
Lemon's silence about his role in the case amid his continued coverage of it immediately sparked comparisons between him and former CNN anchor Chris Cuomo, who was recently fired by the network for meddling in the sexual harassment scandal of his brother, then-Gov. Andrew Cuomo.
CNN had been widely criticized for allowing Cuomo to continue reporting on the network amid his brother's scandal.
According to the Post, commenters on Twitter called Lemon a "crook" for not disclosing his involvement, adding that it was time for CNN to "bid him goodbye," as well.
"Did CNN’s Don Lemon Pull a Chris Cuomo?" asked one blogger.
New York Times best-selling author Tony Shaffer tweeted, "Really, @donlemon? Did you do for @JussieSmollett what @ChrisCuomo did for his sexual assaulting brother @andrewcuomo?"
"They’re a network rife with predators and perverts," he told Fox News. "Lemon will have to testify under oath in the near future, but it’s good to see that there’s finally some accountability happening."