The article body claims the stall warning device was developed for two different reasons, one for deep-stall and the other to avoid spins. Maury Markowitz (talk) 12:16, 25 August 2014 (UTC)
To enter a spin one must first stall, so the answer is, for both reasons, as in addition to the deep-stall the Javelin had a very flat spin, which was also unrecoverable from. At the time of its service the Javelin was the only RAF aircraft for which stalling and spinning were expressly prohibited, for obvious reasons.
The Javelin is IIRC mentioned in Air Crash Detective by Stephen Barlay, which shows an aerial photo of the crash site of a Javelin that either deep-stalled or flat-spun into the ground. Whilst appearing almost intact from the air, the aircraft is quite flattened.