Actually, no. There were 2 confirmed incidents. One involved a person(I believe the mod was a BB) who had his jaw broken when the batteries discharged. The BB does have a vent(under the switch), so I'm not sure exactly how the injury occurred.
The other involved a person who almost had his eye taken out by an atomizer(luckily he was wearing glasses, which were blown off his head). This incident involved a Chuck. The batteries in the Chuck discharged and the atomizer exploded off the end and became a projectile(which hit his glasses). Also, the hot discharge gases through the atomizer, blackened half of the persons face(although no permanent burns). The Chuck is vented as well, so it's apparent the venting on the mods, at least in these 2 cases, was insufficient to handle a quick Li-ion battery discharge.
In both cases dual stacked Li-ion batteries were used(either 2 CR2's or CR123A's in series), and , also in both cases, there was an apparent level of user error involved as well. In the Chuck case, there is a suspicion that possibly non-rechargable batteries were accidentally placed into a charger then used(which, obviously would lead to a dangerous situation).