Ukrainian military authorities are not taking credit for this.

They are attributing it to sloppy Russian safety procedures and and ammo handling practices; which may indeed be the case. Still, even if the Ukrainians DID pull this off, I don't think they want to give Putin any excuses to do something in retaliation. And if they do have some means of doing this again, they certainly don't want the Russians to implement counter-measures.

Still, whether or not it was a Ukrainian missile (or sabotage) the Russians will never know for sure and will still have to implement expensive security and safety protocols.

Perhaps this is why there has been so little reporting of this incident from American news agencies. My guess is this, like the attack on the Russian ammo supply ship, may hint at some Ukrainian intelligence or operational capability they would rather keep in the dark for the time being.

Pure speculation on my part: I think there are certain measures (like those Polish MIGs, or maybe even the infamous 'no-fly zone') which are not easy to implement in a hurry but which are hastily being assembled in the background. No one wants to give away the plan prematurely so Putin can take counter measures..

The Ukes have shown themselves to be very good at distraction, misdirection and PsyOps.