The first time we looked at ACI Research’s chief (and only) tech analyst, back in January, he was telling his clients to sell Apple (AAPL) short.

The stock was trading for $450 at the time and was about to begin a run that would take it to $644. That didn’t stop CNBC from booking him as a guest and giving him six minutes of free publicity.

The second time we visited Zabitsky, he was singing the praises of Microsoft’s (MSFT) Windows 8 and predicting “violent disruptive change” that would soon “shak[e] to the ground” the “entire cellphone and computing ecosystem.” He was on CNBC the next day.

Zabitsky issued another sell short rating on April 19 and was booked once more CNBC, where he warned viewers that Apple’s days were numbered.

Four days later Apple reported blow-out earnings and the stock shot up more than $50 in after-hours trading.

We got yet another Apple note from Zabitsky on Thursday. Same $270 price target. Same advice to sell the stock short. No apology to anybody who might have followed his earlier advice and lost their shirt.

Maybe this time the bookers at CNBC will resist the temptation.