I mean, seriously, how hard is it to pick up the phone or just leave the item in the fridge till the person comes home and simply ask.
I found this dodgy jar in the fridge, want me to throw it out?
I don't understand taking liberties with other people's stuff no matter what it is.
I'll just add... even when it is in your own home. I can't tell you how many times my DH has gotten over zealous cleaning out the fridge before trash day and I awake the next morning to a lost project. I've had dashi broth, cheeses, ice cream base, and preserved eggs thrown out. I know label everything. But it amazes me that he never opens up one of the 5 jars of salsa in our fridge to see if any of them have started growing fuzzies.