No, it's right. ILWU (the union) leadership has made statements such as
"Organization from outside groups attempting to co-opt our struggle in order to advance a broader agenda is quite another and one that is destructive to our democratic process and jeopardizes our over two year struggle in Longview." [1]
So I may not have been right about them speaking out specifically against the Oakland shut down, but in general the union leadership is against strikes. Although, of course, they take great pains to not alienate potential ideological allies while rejecting calls to shut down ports.
The sentiment is at least mixed, as you can see from other coverage: [2]
"Leaders of the ILWU, which represents thousands of longshoremen, spoke out in recent weeks against the coordinated effort by Occupy protesters to blockade ports from Anchorage to San Diego"
"This is joke. What are they protesting?" Christian Vega, 32, who sat in his truck carrying a load of recycled paper from Pittsburg said Monday morning. He said the delay was costing him $600.
"It only hurts me and the other drivers. We have jobs and families to support and feed. Most of them don't," Vega said.
[1] http://www.motherjones.com/mojo/2011/12/occupy-oakland-west-...
[2] http://www.huffingtonpost.com/2011/12/12/occupy-oakland-port...