I do not think its a bootlegg at all. Everythinbg looks legit. The seller probably did not know the mkt value of the item he was selling and the meber was there at the right time.
Secondly, why would some one or a company make a bootlegg with a such exceptional quality (Based on the photo). If he or she had that much of a talent to make Gakken alpha boot, that person would more than likely use that talent on some other collectables that are far more profitable, before making boot or Gakken alphas or cyclone.
The last possibility is that it could have been the one and only AARAFAT, the one and only MW member (I should say former member) that has tree that grows macross and robotech items, espicially Bandai GBP armors, in his back yard.
He might just have visited the PMX to share his wealth with other collectors. (Gosh, I wish I had some time to put some fear into that iditos soul).