Your hands not being covered most likely would have not caused this. From what you said happened; I would assume that either there is a problem with the connection or electro-static discard happened.
If there was a problem with a connection I would recommend trying to disconnect and reconnect the screen cable to see if it fixes it. If this doesn’t fix it, then you might have a damaged cable from changing the screen. These cables are generally very sensitive and you have to be careful with them.
Electro-static discard (ESD) is another very real possibility of what happened. ESD happens when you build up static electricity in your hand and it basically shocks the components in the phone. You normally don’t notice ESD until you test the functionality of the phone. If ESD happened to another component in the device then you might have to get a device. Though if it did happen only to the screen (which it might have) then you might need to get a new screen.
From what you have said the; best thing you can do is to try disconnecting and reconnecting the screen and if that doesn’t work than you may need a new screen. Note though that their may be more factors causing this such as pressure on the screen from the inside of the device. Images of the device’s screen may be useful to further diagnose the problem.
Edit: You can also try cleaning the contacts with 100% isopropyl alcohol. Use only a little