Tony Fernandes is pissed with Gillem Tulloch, founder of Hong Kong-based research firm GMT Research, for urging clients to sell or short AirAsia’s stock for lack of transparency in its accounting practices and alleging in a report that the airline overcharged its associate airlines for aircraft, maintenance and other services to artificially boost profits. “The point is that if profitability does not improve from these levels soon, AirAsia is bust,” Tulloch wrote in an email to clients. “If it improves, as AirAsia believes, then the company still needs to raise $1.9 billion.” The development was enough to send the stock of the Malaysia-based low-cost airline — Asia’s largest —crashing 28% to a five-year low. “I am so damn determined now to shut some people up. I’m best when my back’s against the wall. We aren’t going to give up because of one report,” an agitated Fernandes was quoted as saying.