Between (2) and (3) you were probably working illegally (not sure for how long). However, when you were filing for AOS, you did not have any signle day of illegal work since the latest entry. So, I do not see a reason to deny I-485 because of illegal employment.
Now, let's analyze what lying on the I-485 form gave you.
Whether you had status L-1 or H-1 or no status at all between (2) and (3), was irrelevant, because your visa did not become invalid because of your illegal work or illegal stay. You just had some period of illegal work, that did not harm you at all.
It made no sense for you to hide that fact therefore. It also made no sense for you to hide anything else. So, even if you misrepresented a material fact, that could not be for the purpose of getting an immigration benefit for which you were not eligible. You were still eligible even if you were illegally in the US and worked illegally between (2) and (3).
Start with motion to reconsider. It should do the job.
Now, let's analyze what lying on the I-485 form gave you.
Whether you had status L-1 or H-1 or no status at all between (2) and (3), was irrelevant, because your visa did not become invalid because of your illegal work or illegal stay. You just had some period of illegal work, that did not harm you at all.
It made no sense for you to hide that fact therefore. It also made no sense for you to hide anything else. So, even if you misrepresented a material fact, that could not be for the purpose of getting an immigration benefit for which you were not eligible. You were still eligible even if you were illegally in the US and worked illegally between (2) and (3).
Start with motion to reconsider. It should do the job.