Excess headspace in carboy

I just transferred my midwest java stout kit from primary to secondary. Added coffee and scrapings of 3 vanilla beans to it. Smelled and tasted great coming out of the primary, but had a problem with my autosiphon and couldn't get the last 3/4 of a gallon, so I have a lot of headspace in the carboy.

Since I was concerned about oxidation, I sprayed released some inert gas into the carboy (I have this for wine making and preservation) before stopping it. Anything else I should do? Top it off with some spring water? Ignore it?

Thanks in advance for the responses...you guys are great on here.

no worries. it will be fine. i have had 5 gal in a 6.5 gal carboy. no problems

Souds like it should be fine as is.

Next time you can just rack it to secondary and put the airlock on. After its all sealed up swirl the carboy a couple times, this will cause the release of CO2 from the beer and help to purge the head space.