Any inflated tire assembly carries the potential for a lethal explosion.
However, the true "split-rim" -two rim halves held together by a band- are considered the most dangerous type. The band is held in tension and is relatively light and prone to rust through and deterioration of the holding area at the "C." These rims are known to spontaneously separate even after being assembled and in service. The true split-rims are no longer manufactured, and there previously had been an all out industry effort to get them out of regular service, and replaced by the lock-ring type, multi-piece rim.
The multi-piece rims, which use lock rings held in compression at the beads, are still in production today, and are often erroneously called "split rims." This type of multi=piece rim is most commonly used with current production tube-type truck tires, and "O" ring sealed off-road tires. Once properly assembled and inflated, these lock-ring retained, multi-piece assemblies, are relatively safe; much more so than the true split-rims.
Regardless, it's good work practice to avoid being in line with the projectile, or bead side, of an inflated tire assembly. But that's not enough; in the event of an explosion, even if the flying parts miss you, there's still a potential for a blinding or deafening air blast.
Tire mounting is serious business, with no room for experiments.