Whenever the I/P Validity Change task is completed on the I/P Validity Change Notice workflow, the "Last Modified" date of I/P is updated with the current timestamp and the "Modified By" user name of I/P is not updated (retains the username who actually iterated the I/P).
we are using persistenceserverhelper api's which update without checkin checkout but does update modify date
Sorry I am unable to upload screenshot due to Security concerns .