If we left the front door to the bank open all night, and the door to vault, to boot, would we be saying the next morning that we weren't going to go into the vault and see if all the money was there unless we spotted signs on the outside that it had been robbed?
No, the first thing we would do would be to go in and see if all the money was there. We'd recount it, to see if it matched what the count had been when we put the money in there.
So it is, we should handle our election the same way. If someone shows us the system in hackable, and is vulnerable, and could have been hacked -- if we learn we left the doors open all night -- then we should recount.
The question is simply whether the computer scientists are correct in saying the system is hackable. If it is, then you recount.