SCSI bus instability

[hpnetraid]

Hi,let's speak about a LH3000 with 2 RAID1 (total 4 disks),
a netraid board "1si" integrated on Motherboard (with single bus),
MS w2k sp4, in production for 3 years, well working.

Somebody has made an upgrade with 2 new disks to make a third RAID1
without shutting down the server trying to create a new logical disk with
Netraid assistant. There was an error: "disk configuration not found".
I think this is normal.What do you think about ?

Next he made shutdown to upgrade RAM and then tried to boot.

Question1 : is it possible at this moment the server doesn't boot ?
The reason : an hardware fault on netraid board and/or on drive cage.
This hardware was well working five minutes before !

Now somebody has realized he has to upgrade firmware on netraid
and on main board BIOS and the server was successfully booted.

Now he has initialized the new disks, but at this moment all data on old disks
were become completely not readable.

Question2 : the reason for this data destruction is the hardware fault
on netraid and/or drive cage that has produced a SCSI bus instability.
What do you think about ?
Is it possible ?
Do you know something about this "SCSI bus instability" ?

Thanks in advance.