Thanks for your query.
The diagnosis of heart attack
is based upon history, ECG findings and chemical testing. Only historical perspective can be evaluated by your query and by your description this may or may not be a heart attack but on can not 100% rule out this possibility. Some patients, although atypical, can present with these features.
A normal TMT test by no means guarantee that subject will not have heart attack in future at any time.
I would request you to show him to your doctor in emergency.