If the Toaster is actually damaged, I would say that is unrelated damage.
Hooking up SCSI chains wrong can cause errors on your hard drive, invalidated partitions on other SCSI disks, etc, but I don't know of any failure mode that could hurt a video-slot card, other than a massive shorting or electro-static discharge (ESD).
Of course, hooking up a SCSI device wrong could have corrupted your installed Video Toaster SOFTWARE, which might make the board appear to be malfunctioning.
Where is the A3000 failing in the startup process?