Asking this on behalf of a friend. According to him, he drove over a nail like object that was about as thick as a paperclip but was quite hard to bend (probably steel), the item pierced the tyre tread approximately 1cm (maybe less) in the thread but from an angle, unfortunately he didn't pull it out very straight as he twisted and turned it to remove it. He took it into a tyre shop (tiger wheel) and they removed the wheel, dunked it in water and found no puncture and there appears to be no air leaking according to him. They told him that there was no puncture so no need to do anything. They put the wheel back and he left. Now he wants to embark on a long journey and just wants to make sure that the small hole left won't be a problem on the road, he says he can see a smallish hole on the outside but his not sure how deep it goes. He sent me this picture with the highlighted pink area representing the general area the item was stuck in. Tire has been on for about 4 years but according to tiger wheel, still got a tread depth of 5mm so still safe to use. Will it be a problem on the road?

