backlight would not light up, EMI bottom left screw ring ripped apart

So over the weekend i decided to replace the old battery of my iPhone 6s with a new one to prevent it from slowing down. During the removal process the bottom left screw of EMI shield was pretty tight and in the process the ring (the circular nut) into which the screw drives into came apart as well. Earlier i didn't pay much heed to it but when i turned on the screen it apparently had a crack like damage and upper part of the display went crazy. Probably the damage was due to the ring ripping apart. So when i proceeded to fix it by reseating the digitizer cable, i think i blew up the backlight fuse as the phone turned black but i could faintly see the screen and it was detectable in itunes.

Then i proceeded to buy a new screen as i thought the backlight is part of the screen but the new screen showed the same darkness.

I then took it to an expert repair man and he first said it's the backlight fuse but the phone didn't come alive after repairing it, and then he looked at the ripped up ring and said that the ring has basically damaged the interrupt line to the CPU and now the NAND is fully filled up with errors.

Am a bit confused as before taking to him i could see the screen under the flashlight but after he attempted repairs to the phone it broke even further..

Is there any hope left to repair the phone? All i want is to extract the pictures from the phone and stupid thing is under the passcode which i can't enter without a functioning screen. So much for touch screens :(.

Here's a link to the damage:[ https://imgur.com/a/Gef6c|damage]