No we can't because I've never seen Oscar give any reason as to why he left. Therefore, as there is no evidence in the public domain, you are speculating again.
Some definitions for you:
A FACT - Something which can be backed up by other sources e.g printed media, documents, interviews etc.
AN...
And I've seen nothing that backs up your opinion either. Still goes with the other 145 posts of largely speculation with a bit of bollocks thrown in for good measure.