Arizona Sen. John McCain raised eyebrows Thursday with a string of questions during James Comey's hearing that many observers found confusing — and downright bizarre.

McCain, the final lawmaker to question the former FBI chief, seemed to conflate the federal investigation of Russian election interference with the Hillary Clinton email probe.

The veteran lawmaker then appeared to suggest the FBI was guilty of a double standard, effectively clearing the former Democratic nominee for her use of a private server while keeping the heat on President Donald Trump and his campaign associates for their possible ties to Russia.

“In the case of Hillary Clinton, you made the statement that there wasn't sufficient evidence to bring a suit against her, although it had been very careless in their behavior, but you did reach a conclusion, in that case that it was not necessary to further pursue her, yet at the same time in the case of Mr. Comey you said that there was not enough information to make a conclusion," McCain said, confusing Comey for the president.

Related: 9 Key Moments from Comey's Blockbuster Testimony

McCain later asked, "You're going to have to help me out here. In other words, we're complete, the investigation of anything that former secretary Clinton had to do with the campaign is over and we don't have to worry about it anymore?"

"I'm a little confused," Comey replied.

Twitter lit up with snark about McCain's inquiries. In fact, the McCain/Comey face-off was the most-tweeted moment of the blockbuster hearing, Twitter said.

I'm honestly confused with McCain's line of questioning. McCain wants to know if the Clinton camp colluded w/ Russians so they could lose? — Kyle Griffin (@kylegriffin1) June 8, 2017

I am confused about what point McCain is trying to make here? — Chris Cillizza (@CillizzaCNN) June 8, 2017

These are the top Tweeted moments from Former FBI Director Comey's testimony in the Senate pic.twitter.com/Ew9xcRAFNg — Twitter Data (@TwitterData) June 8, 2017

McCain responded to the online chatter with a winking statement that said, in part:

I get the sense from Twitter that my line of questioning today went over people’s heads. Maybe going forward I shouldn’t stay up late watching the Diamondbacks night games. What I was trying to get at was whether Mr. Comey believes that any of his interactions with the President rise to the level of obstruction of justice.

... to which the Arizona Diamondbacks said:

An associate of McCain said the senator was distracted because he had to take a phone call during his round of questions.