Correct. If he tries to make throws like that in the NFL, he'll have a very short career - back-footed heaves downfield are a recipe for destruction, no matter how strong of an arm you have. This is why it's so dangerous to draft based upon measurables - guys like Allen often end up relying solely on their arm talent to bail them out of trouble and ignore fundamentals like footwork and play design, and that's why they flame out.
Allen might make it - but to me, the odds are stacked against him and I didn't (and still don't) feel that the Bills should be in the risk-taking game at the QB position.