I looked around a bit but couldn't find anything in the bitcoinj documentation.
https://bitcoinj.github.io/networkingSince you're not using bitcoinj yourself the only thing I can think of is that the "via 127.0.0.1:8333" is a part that's just sent from the connecting peer, which means it could be set to any value depending on their client and probably means nothing.
I can't figure out more than that and you'd probably have more information if you asked around the bitcoinj community rather than here.
Or since you already know his IP you could like, just ban him. :p