One question, did you try tightening the plug again, just torque it another 1/8th turn? I have never replaced those washers and to this day, have never had an issue with leaks. I suppose one could argue if the drain plug hole was tapped at an angle that could cause a leak.
Secondly.....why toss the oil at 1000 miles and especially why toss a perfectly good oil filter?
I work at a mitsubishi/hyundai dealership. I much prefer the hyundai washers and we change them every time They're interchangeable too...I researched crush washers and in my opinion, Mitsubishi uses the best crush washer design.
Mitsubishi OEM Oil Drain plug Gasket - Mitsubishi ES 1997-1998,2000-2004 | MD050317 | Rallysport Direct
Get a new Oil Drain Plug Gasket the next time you change the oil on the Mitsubishi Evolution.www.rallysportdirect.com
My wife's Fusion's original drain plug had a washer "built in" but came loose and was lost at some point. It would leak slightly before I realized it was missing. Once I realized this, at the next oil change, I just started using the Honda aluminum crush washers we have.Jeep cherokees have the rubber built into the plug for sealing..
I've done that forever with our Hondas. If I don't remember if it's been flipped and re-used previously, I just replace it.On the civic I found if I torqued the drain pan bolt to 21 ft lbs, I could use the washer twice, I could flip it over and use the non crushed side for the second oil change. I know it was being cheap, but it can be done.
For future posts, just leave out any "controversial" aspects of scenarios like this. You even mentioned this in your OP and people still had to spout off their opinion about it....I knew I was gonna get flak for dumping 1k oil