If any of my customers have the same problem, it is true that the drives normally get returned to the Mfr.
If you imagine that most Mfr's get 1000's of hard disks back every week. What they normally do is dump the platters (internal disks) and repair the drive and add new disks inside the unit.
They wouldn't normally be bothered about looking at anybody's data - would be counter productive and also definately not make commecial sense. Also I would think that is this was ever found out that they would be in a bit of trouble, not only legally, but with a slagging off in forums like this.
I expect that evesham will allow you to pay for the drive and keep it - you would then be able to destry it, or even open it up to take a peek if you are interested in the internal workings.
Personally I wouldn't be too worried about it - hope this helps...