I'll be the contrarian - It's probably stripped
because someone was using a torque wrench. :
The torque spec is for dry threads. An oil pan plug is instantly lubricated threads once it's in service and trying to torque to to the dry spec will significantly over tighten it. It's an oil pan plug, it needs to just be tightened until it stops against the washer, (you did use washers, right?), then snugged a tiny bit more and it's fine. The actual torque value is moot. It's not a moving part, it's not holding a moving part. The value is intended to prevent damage, but it's the wrong value since engineers always use dry torque specs and every spec in the FSM is dry torque unless otherwise noted.
Few drain plugs get stripped because someone reefed on a regular wrench or ratchet so hard they did damage. But a long handled torque wrench gives a lot more leverage. Add to that the incorrect dry thread torque spec being used and yes, it's surprisingly easy to strip the aluminum threads. Note that a further problem is the torque wrench itself! Many average +/- 25% error depending on where you are in the range.
Torque wrenches are generally set at the middle of the range and err on either side of that to some degree, becoming less accurate the farther away from the middle of the range you are. This is even true of high quality tools, but can be extreme in budget quality tools. Because of this, try not to use a big torque wrench at the bottom of it's range for anything important. It's likely going to be inaccurate and the potential for a problem is greater.
Skip the torque wrench!!
If you just can't stop yourself, don't try to tighten it to the spec listed in the manual. That is a dry thread specification. Reduce that by 20% for wet torque and you'll be better off.
I have two main torque wrenches, one is a fairly standard 30-150 ft/lb version, the other is a 50-250 in/lb version. (12 in/lbs = 1 ft/lb) If you do the math, you will see that they don't quite over lap, the in/lb version only going up to slightly over 20 ft/lbs, but the two cover 95% of my needs. These happen to be Mac Tools with metal internals and have been calibrated. Note that you should
always store your 'clicker' type torque wrenches backed off to zero or the minimum setting to avoid fatiguing the spring which will accelerate the error factor of the tool.