The real-life reason for this wild spiraling behavior would be that the launch tube isn’t pointed directly at the target and the missile overcorrects. That’s actually how the sidewinder missile got its name.

This kind of mid-flight course change is a characteristic of real missiles in other cases , though:

* almost anytime a submarine or ship launches, the missile goes straight up for a little bit to clear the ship before sharply turning

* if you shoot a guided missile straight up unguided to clear terrain (eg a hill) before turning on guidance you’ll see this

* cruise missiles in the gulf wars famously did this by following the street grid - even turning at street light

* if you launch a torpedo in a random direction then activate guidance later it can disguise where you are, since the torpedo is coming from a different direction