100 connecting devices frequently fail auto-neg on gig ports. This will generally either come up half duplex or not connect at all as you seem to be experiencing.
The solution is to configure the junos port to turn off auto-net and set the speed and duplex manually.
set interfaces ge-0/0/11 ether-options no-auto-negotiationset interfaces ge-0/0/11 ether-options link-mode full-duplexset interfaces ge-0/0/11 ether-options speed 100m
Sorry for missing the point.
OAM is just the detection mechanism so it can see if a point to point link fails but you would need something else to take action on the failure. I've only used it as part of a trigger for lsp path switchover when link failures are detected.
In your case it would log and dectect the link failures but since there is no alternate path I'm not sure what you could tie the events to for an action to take.