Rep. Elijah Cummings, who sparred passionately with House Oversight and Government Reform Chairman Darrell Issa during a public hearing last week, is questioning whether Issa's actions to end the hearing may have let former IRS official Lois Lerner off the hook from potential criminal contempt proceedings.

Cummings continued his showdown with Issa in a letter to House Speaker John Boehner Wednesday that argues Lerner's potential prosecution would likely be dismissed because of a procedural technicality if the House were to move forward with a resolution of contempt.

Lerner, the former IRS director of exempt organizations, first refused to answer questions from members of the committee at the May 22 hearing last year. But that day, when Lerner read a statement aloud and authenticated a document for the record under oath, questions arose surrounding the validity of her assertion of her Fifth Amendment rights. Republicans then ruled her actions waived her right to refuse to testify.

Issa, R-Calif., had left the hearing in recess so that the subpoena would remain in effect and the committee could potentially compel Lerner to reappear before the panel at a future date.

But last week, when Lerner finally came back and continued to assert her constitutional right not to testify, Issa repeatedly attempted to adjourn the hearing and dismiss the witness and committee members.

In a memo sent to Cummings, D-Md., Wednesday, Morton Rosenberg a former emloyee at the Congressional Research Service who consulted on the matter with the Democratic Minority, concludes that "requisite due process protections" mandated by the Supreme Court to prosecute a witness in contempt of Congress "have not been met."

Rosenberg notes that Issa committed an error when he adjourned the hearing last week without making it expressly clear to Lerner that refusing to answer questions would definitely lead to criminal contempt proceedings.

"At no time during his questioning did the Chair explicitly demand an answer to his questions, expressly overrule her claim of privilege, or make it clear that her refusal to respond would result in a criminal contempt prosecution," Rosenberg wrote. "At no state in this proceeding did the witness receive the requisite clear rejections of her constitutional objections and direct demands for answers nor was it made unequivocally certain that her failure to respond would result in criminal contempt prosecution."

Stanley Brand, a former House counsel, added, "Making it clear to the witness that she has a clear cut choice between compliance and assertion of the privilege is an essential element of the offense and the absence of such a demand is fatal to any subsequent prosecution."

In his letter to Boehner, Cummings notes that the analysis completed at his request found that Issa cannot undo his apparent mistake because when he adjourned the hearing last week, Lerner was released from the subpoena that compelled her to twice appear before the committee.

"This analysis, solicited on a partisan basis, is deeply flawed and at odds with the House's own expert legal counsel to the Committee," Frederick Hill, spokesman to Issa, wrote in an email. "At the hearing, Chairman Issa specifically informed Ms. Lerner of the Committee's formal determination that she had waived her Fifth Amendment right not to answer questions. Before asking a series of questions, he then offered her fair warning that a refusal to answer could lead to a contempt finding, which ultimately must be made by the full House of Representatives."

Nevertheless, Democrats contend the analysis "stands on its own."

"Their partisan allegation is that we asked for this analysis on our own," a senior Democratic Oversight committee aide said. "Yet they have been excluding Dems at every stage - in negotiations with witnesses, from speaking at hearings, and in discussions with House Counsel."

The committee took no action this week regarding Lerner's situation, but Issa has signaled he could move a resolution of contempt as soon as the week of March 24, when Congress returns from a week-long recess. A spokesman to Boehner deferred comment.