what are the low rating part(s) of this series in your opinion

first of all I should say that this is the best series I have ever seen

I would say 2 parts

the first part is when gustavo comes out of the door and dies.because it wasnt realistic at all there was a big explosion and he just walks out ?it is impossible to stay on your feet but he just walks out and .... it was the worst part in the series

the second part was when walter shooted mike in the stomach and he died in 2 or 3  minutes.I remember he was shot 2 or 3 times before and he survived even after the doctors finished their job with gustavo but this time he just dies very quickly.I think he died because the writer wanted him dead