That was anchor failure.
Those anchors are available in a much deeper length. those short ones just yanked right out. It's also possible the holes wern't drilled the right size or reamed out to much for the anchors. If they couldn't go any deeper than that, then should have poured a core for each post.
We use those all the time at work. They work great on about anything. SOP is to drill all the way through the concrete. Then when you move the machine (or whatever else) you just remove the nut, move the machine, and then pound the stud all the way flush with the floor.