The question is whether or not the offenses allegedly committed by CJ Corona are impeachable offenses.
In particular, is the error in accomplishing the SALN (Statement of Assets, Liabilities and Networth) a sufficient ground to impeach a chief justice? Is CJ Corona guilty of betrayal of public trust?
Anyway, to have a clearer background on what constitute betrayal of public trust, read the article of Fr. Joaquin G. Bernas, S.J.
For law students, take note of the meaning of ejusdem generis, a principle in statutory construction.
