It's no real surprise the nurse said it looked normal.. They're not the easiest things to read. When I worked in a hospital some years ago I was part of a ward entourage with a consultant. When he got to one bed he picked up the ECG trace that had just been done and was thumbing through it going "hmm, ah hmm! mmmm, hmm, uhu, uhuh" and so on. Each of us looked on until one brave young man leant over his shoulder and said "it's upside down sir". He continued hmming and ahhing before turning to the young medic and saying "you have to be very good to read them upside down you know!"
I wouldn't really expect this of a senior physician, and most any **** can see something basic like a prolonged T-wave. But in the grand scheme of things, they're not easy...