This might be a bug. Perhaps a different value was intended to be returned.
The rule is only violated if all return expressions are identical. Flows that do not return anything or only have one end event will never violate this rule.
Disclaimer: We expect that this rule will trigger violations which are “false positives” i.e. violations that are not really something that needs your attention. In our view, the cost of a false positive is not as high as the cost of missing a bug. A false positive is easy to whitelist. On the other hand, a bug that ACR fails to detect can have large repercussions and costs in terms of development time and customer satisfaction. Therefore we will keep this rule as is in the hopes of catching bugs and accepting the occasional false positive.