Hearn wants League One Orient to be able to share the ground with West Ham and believes the decision made by the London Legacy Development Corporation (LLDC) breaches their own rules.
Hearn has launched a judicial review of the LLDC's decision and remains hopeful that he will be successful.
"We have applied to the High Court for a judicial review regarding the Olympic Stadium," said Hearn. "And we think today's announcement is jumping the gun.
"The decision of the High Court will concern whether the bidding process rules were followed by LLDC.
"We say they weren't, and that we weren't given the opportunity to enter into the 'teaming' (groundshare) discussions that the bid process allows.
"We think this is a fundamental flaw in the bidding process and we're applying to the High Court for a ruling to sling the whole lot out. They may have jumped the gun."
Hearn believes Orient, whose Brisbane Road ground is less than three miles from the Olympic Stadium, will have to move if they are not able to share with West Ham.
And he is also angry about the terms of West Ham's Olympic Stadium tenancy, under which the government will pay a large chunk of the renovation costs.
"The bidding process rules were agreed by everybody," he said. "West Ham, Leyton Orient and the other bidders, agreed to the principle of 'teaming', and yet we weren't allowed to investigate the possibilities of teaming, which would have allowed Leyton Orient to survive.
"We are the community club, not a multi-million pound commercial enterprise, clearly now being sponsored by the government.
"We didn't think Leyton Orient sharing the ground harmed anybody, in fact we thought it added to the mix.
"What we're left with is a situation where the government, and Newham Borough Council, are clearly subsidising and sponsoring a major commercial enterprise, paying for it out of taxpayers' money.
"I don't think West Ham wanted to share and there are some interesting questions to be asked about what deals were done in corridors or whispered behind people's backs about what assurance was given to West Ham that there wouldn't be any other football club at the stadium.
"We think the LLDC has made a massive mistake, so we'll let the lawyers in the High Court decide and see where we go from there.
"This is a David and Goliath situation and I know everyone would rather I went away, but the sad news is that I'm not.
"We've got a little tiny community football club being steamrollered by bureaucracy. If anyone needs help, which is surely the whole point of the Olympic legacy, it has to be the local club.
"We need a chance to live our dreams as well."
There seems to be such a huge opposition to ground sharing in this country, I can understand football owners and clubs wanting their own patch, but how can politians not see the advantage? West Ham are only going to using this stadium once every 2 weeks, why not have Orient (or even tottenham?) playing the other weekend? They can pay rent in the form of percentage of gates receipts, might not be much but any money coming in is better than more tax money! We have recently seen Don Valley in Sheffield close down because it was a one-sport stadium. Some of the feircest rivals in the world share stadiums to their mutual benefit!- nedbowthai