Thoughts on this flue

[Gary Gas]

Installed 2 days ago, Worcester 4000. Haven’t seen anything like this before, any thoughts.
Personally I would have gone horizontal with an offset bend in the roof space ( to get minimum distance from boundary) and terminated at the gable end.

 

[ShaunCorbs]

It’s fine but the joint needs to be sealed with silicone and there doesn’t look like a lead slate

 

[Deleted member 120897]

Also looks like it could be too close to neighbouring property, boundary?