In a marathon hour-and-a-half press conference, Montag-Girmes kept his cool and introduced himself as a corporate finance expert with 30 years' experience.
He denied his €52m contribution to airBaltic's balance sheet came with strings attached - such as the purchase of Sukhoi jets - saying "My investment is completely separate from the choice of regional jet. There is no obligation to buy any particular type of aircraft."
Montag-Girmes also maintained that the money he was investing was entirely his own.
"The only person I am representing is myself... this is the biggest single investment I have ever made... all of this money actually comes from my private funds," he told LSM.
He denied he was a security risk because of his business ties to Russia and confirmed that his business operations were based in Cyprus.
His interest in airBaltic was piqued after seeing airBaltic chief executive officer Martin Gauss giving a presentation at the Paris Air Show in June, he explained, and said the fact that he had set up Latvian-registered aircraft leasing companies in December 2014 was a "pure coincidence" related to another potential deal with an unnamed client.
In contrast, airBaltic chief executive officer Martin Gauss, usually a study of ice-cool demeanour, seemed genuinely angry after encountering government's inability to make decisions, breaches of confidentiality agreements and wild media speculation that threaten to ruin the deal approved by the Latvian cabinet a week ago.
"It's very sad what is happening around the most positive decision in the last four years in Latvia. It's very sad how it happened because what we achieved last week was a positive decision from the Latvian government to approve an investor and secure the long-term future of this airline.
"The result after six days is a complete political mess which has nothing to do with this successful airline. It makes me really sad seeing the international media congratulating me on our investment, on our [Bombardier CS300] launch customer status and being successful in the Baltics and I return to Latvia on Monday and I come to a very, very difficult environment."
"I will not get involved in politics but this is not okay what is happening: a lot of rumors, a lot of breaches of confidentiality at all levels which I really would not tolerate and then a lot of wrong information spread."
After the press conference, Mr Montag-Girmes spoke to LSM explaining how he got involved with airBaltic in the first place and how he hopes his investment will pan out.