Are you sure? Not only are the remains identified as originating from a S300, but the S300 is not only an anti air missile, they are used to strike targets as well.
The original warhead weighed 100 kg (220 lb), intermediate warheads weighed 133 kg (293 lb), and the latest warhead weighs 143 kg (315 lb). All are equipped with a proximity fuse and contact fuse. The missiles themselves weigh between 1,450 and 1,800 kg (3,200 and 3,970 lb). Missiles are catapulted clear of the launching tubes before their rocket motor fires, and can accelerate at up to 100 g (1 km/s2). They launch straight upwards and then tip over towards their target, removing the need to aim the missiles before launch. The missiles are steered with a combination of control fins and thrust vectoring vanes. The sections below give exact specifications of the radar and missiles in the different S-300 versions. Since the S-300PM, most vehicles are interchangeable across variations.
The system can destroy ground targets at a range of 120 km (19,000 fragments or 36,000 according to various missiles). When launched against ballistic missiles, the range reaches up to 400 km.[11][74]
https://en.m.wikipedia.org/wiki/S-300_missile_system
Plus as I remarked, that crater doesn't even match the crater of the smallest cruise missile.
RE: The missile knows where it is...