You have misheard or mistyped or it has been mistyped. "we are helping out with the investigation'. is the same as "we are helping with the investigation". you can argue any grammar or linguistic rules and cases but it is really pointless to do so, They mean the same and everybody would understand them as being the same.

'whit' is not a conjunction I think you mean "with" 'whit' is a noun, as in "a whit" meaning "a bit" used in negative sentences: She doesn't care a whit about me.