This exact thing happened to my 07 MKZ this weekend. However, i was drag racing my friend in his Infiniti G37. At 60 MPH and maybe 7000 rpm she shut off completely. I rolled safely to the next stop light, turned the key back, then forward to start again. She fired right up and has never had an issue since.
Seemed off to me, I've not had it to a shop - but was sort of glad to see that it's happened to someone else.