Question on dropdowns a!save

There is probably a simple way to do this and I hope someone can help me out.
We have dropdown containing "organizations" on a form with a placeholder label. If the user selects an organization, the saveInto parameters work nicely. However, if the user were to click back to the placeholder label entry, the system produces an error when it tries to execute a rule in the last a!save statement.

I have tried to check for whether the local!org value is null so that the last a!save statement doesn't execute but it still does.
Is there a better way to do this?

a!dropdownField(
label: cons!PLEASE_SELECT_ORGANIZATION,
placeholderLabel: cons!ORGANIZATIONS,
choiceLabels: apply(rule!generateOrgDropdownChoiceLabels, ri!orgList),
choiceValues: ri!orgList.organizationId,
value: local!org,
saveInto: {
local!org,
a!save(ri!selectedPSS, null),
...

OriginalPostID-226271

OriginalPostID-226271