I do not think that this solution is correct.
It will overlook same-as items.

Try this variable with it.
numbers_list = [1, 2, 3, 3, 6, 7, 8, 9, 10, 12]

"3" would be the first non-consecutive item.
But the above function will choose "12"

The check should be whether it is consecutive (+1) or not.