To add a bit of explanation, sending an Item a Command does not automatically or immediately change its state.
Most items have the autoupdate feature left on by default, which you can think of like another binding. Eventually, autoupdate receives the Command and creates a state change for the Item. That might be before or after other bindings have dealt with the command (some bindings will update the Item then, some will wait for a response from an end device, some do nothing), and before or after rules have been triggered by the command etc.
You can have rules behaving more predictably by careful decisions about triggering on command, or on update, or on change.
You can make the Item behaviour different by turning autoupdate off for that Item.