The manually entered value of RadDateTimePicker is replaced with the original one in Batch Edid mode in iPad.

To reproduce this incorrect behavior add a new 

<telerik:GridDateTimeColumn HeaderText="Start Date" UniqueName="StartDate" DataField="StartDate" DataFormatString="{0:MM/dd/yyyy}">
            </telerik:GridDateTimeColumn>

column in the Batch Edit demos of RadGrid and test under iPad. 

Tap over RadTextBox, enter some new date and press Go/tap out and you'll see the problem.