Anyone can call in anonymously to CSPAN, claim to be the IRS and make those statements and it's meaningless.
I've no doubt in my mind what that caller said actually does in fact happen, but absent a name, proof, testimony under oath, etc. I can prove nothing.
Your wrong, there is plenty of proof internally. IRS Employees have to track their time and cases they work on.
Have the new commissioner (after this current one is impeached) get a list of everyone that dragged out an audit by case worker. Review the audits by political leanings. Fire or charge anyone that is not close to balanced. End of story.
I know they can do this, because they had a list of groups that were targeted. That means they have a list of case workers / auditors that did the targeting. Crush and destroy them.