Stealing is Wrong

The reasoning in the lawyer's argument is flawed in that the argument

Lawyer: If you take something that you have good reason to think is someone else's property, that is stealing, and stealing is wrong. However, Myers had no good reason to think that the compost in the public garden was anyone else's property, so it was not wrong for Meyers to take it.

Answer: takes a condition that by itself is enough to make an action wrong to also be necessary in order for the action to be wrong.