Could it have been done better? Yes
It is unsafe/dangerous? Maybe. Other people have discussed this already.
Was the option of hiding the pipe discussed?
Did you discuss your problem with the engineer immediately during or after the installation?
Can you go to a restaurant, eat a meal, pay the bill and then complain? Yes but probably not the best idea.
My recommendation is to call the engineer and discuss in a calm and reasonable matter the problem. If you want a neater pipe then you may get luck and he will do it for free. If you want it hidden, then it will cost you more.
It is unsafe/dangerous? Maybe. Other people have discussed this already.
Was the option of hiding the pipe discussed?
Did you discuss your problem with the engineer immediately during or after the installation?
Can you go to a restaurant, eat a meal, pay the bill and then complain? Yes but probably not the best idea.
My recommendation is to call the engineer and discuss in a calm and reasonable matter the problem. If you want a neater pipe then you may get luck and he will do it for free. If you want it hidden, then it will cost you more.