i've seen this several times, both on my team and the reds. They go to the NW coast and get stuck. The picture is the only one that I have, it was at the end when we killed the poor sap who was stuck there. It never happened to me, but still it sure frustrated some folks.
Another spot in the same map is a little hill with rocks behind it as pictured, tanks will get on hill and then get stuck in the rocks