difference between validation feedback and show message in rollbak

regarding validation feedback and show message,I think the rollback mechanism is working with validation feedback but it is not working show message and that is should be OK in case of the show message of type information or warning but with type error it should rollback Am I right about this?. for example if I have object (A) has a relation with many (B), in the data-view of (A) which has a data-grid relation (B), and I want to validate at least the user must add one B object , the validation feedback cant be used here and thus I use show message with type error which will not rollback the micro-flow.
1 answers

I think an error message should not result in an automatic rollback, I can think of many cases where that would be very annoying. Furthermore there is no need for, since there is a rollback activity as well.