If it wasnt shot down then Boeing are in the shit if another 737 has gone down...regardless of the fact this wasnt an 800max. If a single engine failure has brought down an aircraft in flames then there is a very big problem with those engines.
As you say those pics do look incriminating and together with reports actually saying it was shot down things start to point to an utter catastrophic fuck up.
It's very unlikely and I'd hope almost impossible nowadays. You can count the number of recent uncontained engine failures leading to deaths on one hand.
Southwest did have one with a variant of this plane a few years back but it just turned back and landed.
It's exceptionally rare and even when it does happen, 99% of the time it doesn't do enough damage to really cause a serious problem such as a fire/explosion.