If it was RAID-1 and not RAID-0 or JBOD, then the drives should be exact copies of each other unless the raid hardware did something really weird. Most drives don't have a read-only jumper, that would have been ideal for experimenting. I would try putting one drive into a non-raid controller and seeing what happens. Worst case should be that there are no partitions detected on the drive because the raid controller did something weird or it wasn't RAID-1, just be sure that if Windows detects that you have a new drive and it needs to be formatted that you tell it NO.
I wouldn't put the drives into another raid controller except as an absolute last resort. The controller might not accept the drives until the controller is configured, and the controller may automatically "initialize" the array as part of the configuration.