Everyone's ECG is different - T wave changes can be normal or abnormal depending on your age, gender, anatomy, genetics, medical history, and lots of other factors.
I suspect the "anterolateral T-wave abnormality" and "borderline ECG" comments were the ECG machine's own interpretation. These machine interpretations are very unreliable - healthcare professionals interpret them themselves for this reason. If the person you saw wasn't worried then I'd be reassured, but if you're still concerned I agree that you could see your GP to discuss it and/or repeat one.
Hope this helps!