One of the most unworkaroundable problems I've faced in LSL is the inability to know who or what triggered the changed event in my script. The kludged meso-fixes to the problem are really poor, and have significant flaws to them:
Meso-fixes:
1. Use a sensor.
This "solution" faces problems when dealing with CHANGED_INVENTORY. Anything, anywhere within the sim can add items to the inventory of my object if llAllowInventoryDrop is set to TRUE.
2. Use touch.
This also faces problems. I dont feel like touching my object to make it recognize that I'm the person who's triggering the CHANGED_SCALE.
3. Use volume detect.
See sensor for why this isn't viable.
The only 100% solution to the problem would be either the addition of a parameter to the changed event (key changer) or the addition of a function (llGetChanger) that allows me to get the UUID of the thing that made the change.
==Chris