My question involves labor and employment law for the state of: SC

I work for SC government full time job .
I was offer couple weeks ago a new position with the state in the same area because my present division is going to be absorbed by another location in the same type of work and everybody from my location will be dismissed.
I was requested to go to a internal interview process with several interviewers and on the next day a got a call from the HR offering me the job and giving me all the details including salary, name of new manager, location , expected date for start training, everything ...
The week after this situation i had the same HR people telling me that "the offer was rescinded" because of an investigation concerning another co worker under my supervision (not at the time of the claim) that she was sexually harassed by another male worker about 18 months ago .
At that time i was not her boss but she told me that she received an offer from a guy that was also employed with the same area " for Dinner "...
I was not present on the spot but she told me anyway.
Can i be involved on this situation pending my new position because of an administrative investigation?
Everybody in the location was heard by the HR + company lawyer individually .
Can i make a case of Detrimental Reliance ?
If they decided just cut everybody who is aware of the story i will be laid off .