Can this be a just reason for termination?

ganito po yung story ko, me and my officemate pulled up a joke on someone's facebook account, naiwan po kasi nya nka login yung account sa laptop nung officemate ko, pinalitan namin yung profile picture nya with a barbie picture, nag file po sya ng report sa HR and its being investigated right now, ang gusto ko po sana itanong is, pwede po ba maging grounds for termination nmin yun?

additional details:
probationary pa lang po kami
mron po kami company rule na nagsasabing liability nung nakaiwan ng open account kung ano man mangyari sa account na naiwan nya
inamin na po namin yung ginawa namin kaso yesterday lang po namin inamin, and yung incident is nung sept 5 nangyari

fresh grad po kasi ako and wala pa alam sa mga ganyan, gusto ko po sana ng insights nyo about this, alam ko po napaka childish nung ginawa namin pero grounds for termination po ba yun?

imo, it should not be a basis for termination. written warning at best

sa susunod wag pakialamera sa accont ng may account..saka bago pa lng kyo ah..wag muna ilabas sungay..kukubli muna yan sa likod na batok nyo..LOL

kung profile pic lang naman pinalitan.. i dont think there's any real harm done, and as you said, liability nung nakaiwan nung open account.. so lusot na kayo don..