Don't get caught up with the flare, It's a nice shot, and yes its said time and time again, for long expo lose the filter..
The best way to achieve long expo under harsh and massively contrasting light / dark is to shoot a few shots and blend manually, Not HDR, as this often looks fake, awful and plastic. Expose the scene you want, as you have here, then expose for the highlights, if needed expose one for deeper shadows and blend them together in post.
The being said, you may still suffer flare ("green bits") - From looking at the shot, the angle that the light is hitting the lens is is your only issue, This will be something you can reduce by moving the angle of your lens slightly, however, it's not something to get hung up on, Sometimes it can add to a scene, sometimes it can kill it, sometimes, the content aware fill in PS will do a great job of getting rid of it...
Check through the viewfinder as you will usually see it, it's a nice shot, I'd have taken a few exposures and blended if I wasn't happy with the highlights... sometimes I actually quite like the streetlamp to blow me a star or two...