Absolutely, something is moving.
Mine did exactly that, and whats weird is that since when the front raises the tendency is for it to toe out really screwed with me.
I would be driving down the road just fine and then all of a sudden I would notice a pretty big rolling resistance so I would pull over to find the front end up in the air 2 inches or so, and a MAJOR toe in with the outer sidewalls of the tires even folding under.
Back up ten feet and the front would drop back down to normal and everything seemed fine till it would do it again.
What blows me away about yours is that an alignment guy would align something that had that much play in it.
Either that or something was left loose like already mentioned, but it would have to be something pretty serious to do that.
By chance did you happen to inspect the LCA pivot pins for broken welds or tightness? (A pin moving could cause it)