Washington CNN  — 

The publicist whose 2016 email to Donald Trump Jr. led to a now-infamous Trump Tower meeting said Thursday night he’s not surprised the special counsel investigation did not establish that President Donald Trump Trump or his campaign associates conspired with Russia to win the presidential election.

“People say to me, was I surprised by what we’ve learned so far from the Mueller report, i.e. no collusion – I always thought if my email and the subsequent meeting at Trump Tower formed a cornerstone of that investigation and collusion, then this would be the finding they would have,” Rob Goldstone said on “CNN Tonight” with Don Lemon.

Goldstone, a British publicist, became an unlikely figure in special counsel Robert Mueller’s investigation when it emerged that he emailed Trump Jr. on behalf of his client Emin Agalarov to suggest a meeting regarding potential dirt on Hillary Clinton. Trump Jr. responded enthusiastically and later held a meeting along with top Trump campaign officials, Goldstone and a Russian attorney. The President’s son has contended that the brief meeting focused almost exclusively on the issue of Russian adoptions.

The offer and subsequent meeting have been the subject of investigation, and the topic has re-emerged now that Attorney General William Barr has released his summary of the report.

Barr said in his letter to lawmakers that Mueller’s report contains an extensive examination of Russian efforts to influence the 2016 election, although it is unknown what Mueller wrote about the Trump Tower meeting.

Goldstone told CNN on Thursday that he regretted sending the email and that he “puffed” up information in order to help arrange the meeting for his client. But he stood by his belief that the meeting did not constitute “collusion” and said he had testified as much before different US investigations.

“All I know is what I know, and it’s what I’ve testified five times,” Goldstone said. “I’ve spoken to the grand jury. I’ve been on Capitol Hill. I’ve spoken to the Mueller team. On each occasion, I’ve felt that the story needed context, and when people understood the context, the collusion side of it became less important.”

Mueller’s confidential report on the Russia investigation is more than 300 pages, according to a Justice Department official and a second source with knowledge of the matter. Barr’s four-page summary of Mueller’s report provided only few details of how it is structured, describing it as “divided into two parts.”

A small team at the Justice Department is working on determining what portions of the report can be made public, after scrubbing it for grand jury and other material related to ongoing investigations.