Thanks a lot for your insight. We also believed in the same way, specifically, the victim's request on the resource was for an update lock.
We were and still are a bit baffled with interpreting the deadlock chain. If you did manage to have a look at the .xdl file, in one chain, it is shown, one process has been granted exclusive lock, however, in the chain involving deadlock, another process has been granted Update lock on the same keyid.
Thanks and regards.