Eric Trump; Donald Trump Jr. (Credit: AP/Kathy Willens) After Donald Trump Jr. tweeted the chain of his own emails with British publicist Rob Goldstone, the intermediary for a meeting where top Trump campaign officials intended to receive damaging information on Hillary Clinton from the hands of the Russian government, experts are saying it could get him prosecuted. “This is smoking gun evidence of collusion,” Paul Butler, a Georgetown law professor and former prosecutor said on MSNBC on Tuesday.