The potential problem your friend has is Article 107 UCMJ. This section of the military justice code makes it a crime to give a "false official statement".
It does not make all lying a crime...such a law would not be constitutional for many reasons. But it does make particular false statements criminal, specifically if the false statement is an "official"
Here is what the statute provides
Any person subject to this chapter who, with intent to deceive, signs any false record, return, regulation, order, or other official document, knowing it to be false, or makes any other false official statement knowing it to be false, shall be punished as a court-martial may direct.
What you describe, at a minimum the statement to the general in the context of applying to be an aid would be an official statement. They others may or may not be, again depending on context...but if they were made to enhance his reputation as an officer within the community? It would likely qualify as a crime.
What should your friend do? I would not make any further statements. At all. What you describe, this officer is likely looking at disciplinary action. It COULD include processing for a BOI (board of inquiry). That could lead to their discharge
from the military with an other than honorable conditions discharge. No good reason to give a statement and either lie more or confess. At this point, the best thing the officer can do is assert their right to remain silent, as provided in Art 31 UCMJ.
Please let me know if you have more questions...happy to assist if I can