Advantage roll results in both a 20 & 1

Rolling with advantage, I roll both a 20 and a 1.

Disclaimer: This being in a PBP game I will follow the DM ruling without question when they get on line.

This question is more on how to adjudicate it, particularly for those that 1 always equal "bad".  I assume there is no RAW answer.  The chances are very remote as it is a only a 5% chance to roll one number and rolling both together is less than 5%.

Does it matter which (1 or a 20) was rolled first?  What if on a table two D20s where rolled together? So both results occurred simultaneously?

Being an advantage does the positive affects of rolling a 20 get canceled by the 1? 

If this was a disadvantage does the negative affects of rolling a 1 get canceled by the 20?

RAW, the 1 on the dice doesn't matter at all. When you have Advantage (baring any feat/ability/spell interaction I'm unaware of) you roll two dice. It doesn't matter if you roll them at the same time or not. You always take the higher roll. So if you roll a 1 and a 20, you take the 20. The 1 basically doesn't exist. It's the same as if you rolled a 2 and a 20, or a 19 and a 20. Your roll IS a 20, and the other dice ceases to matter.