Nine of his 10 reasons were fundamental and irreversible. Things like the death of Steve Jobs. The increasing complexity of Apple’s product line. The loss of its ecosystem advantage. And worst of all: “Apple is selling an equal to worse product than the competition for more money.”

Kass spent several weeks spreading his message of Apple gloom on his many venues, from Twitter to cable TV.

Taken to task by Barrons‘ Tiernan Ray, he answered with an open letter that rattled off eight more points, including this one:

3. Apple’s shares have dropped by $50 since my original analysis was published on TheStreet and RealMoneyPro. This has occurred in a generally upward trending market. In other words so far I have been correct on the stock.

If he was correct in mid October, it would follow that he was even more correct this week, when Apple — which was trading for $674 a share when Kass started his campaign — traded for as low as $533.74.

But no. Having helped knock more than $130 billion off Apple’s market valuation, Kass on Friday cheerfully announced that he is buying Apple again.

“Hey, I never said it was a forbidden fruit,” he told the Wall Street Journal. Then he preceded to tick off five reasons he’s turned bullish on the stock. You can read them here.

Here’s the thing: None of his five reasons for buying Apple now address the fundamental concerns he raised in October. Steve Jobs is still dead, Apple’s products are still more expensive than the competition, etc. etc.

He does give Tim Cook credit for completely refreshing the company’s product line (“no mean feat”), which he now says “should be plenty enough new stuff to once again propel earnings throughout 2013.”

But his basic message is that the damage has been done. He and the other Apple naysayers have knocked the stuffing out of the stock — shaking out who knows how many retail investors who had to sell their holdings at distressed prices to meet margin calls — and now he’s ready to pick it up for cheap.

It’s at times like these I’m reminded of my favorite Jason Schwarz quote. It’s from his classic Apple: Seven Reasons Shorts Love It, and it goes like this:

“If you can keep a good stock down then you are able to load up for the ride back up. It’s like a slingshot — the harder you pull, the more propulsion you generate.”

See also: Meet one of the guys tugging on the Apple slingshot.