Yeah I don't think they checked the lean on the base, I think they just checked the figure for any obvious defects (like paint chips, bad jaw seam etc...). Unless they removed the sticker altogether from the base, placed the statue in it then reapplied the sticker.
To be honest though, I took photos of it tonight, and it looks very similar to my previous one. There is still slightly more of a lean than my previous one judging by the pics, but it's not as apparent. I'm thinking maybe it's just an optical illusion, as it looks fairly straight in the pics. It's certainly not perfectly straight, but I'm wondering if any of them are.
SAB and chris, when you place yours dead centre in the base, and position him so that his body is facing front on, foot pointing directly in front, how do his nipples look? Do they appear level or is his right nipple slightly lower than the left?