The resistance is the explosion itself. How does a rocket fly? It doesn't push against the air, it works on the principle of equal and opposite force. That's why rockets can fly in space, they just need air to burn the fuel.Just to make the point, here are shaped charges resting on the surface of a steel plate.
There is nothing holding them still, and their tiny mass is the only possible resistance. Yet they punch through what looks like 10mm steel.
Look at this video at exactly 13:36
See how you first get a huge explosion in the direction opposite to the shaped charge?
We would have seen the shirt puffing up on Charlie's right side first, but we've seen the exact opposite.
Besides, in all of the videos of shaped charges I watched, the capsule itself gets completely destroyed and with Charlie we see that the mic is still attached to that magnet after the event.
If the capsule didn't explode, we would have seen an even stronger jet towards his right side because all the ignited air would need to go somewhere. I would expect to see nothing left of his shirt on that side. It would also catch fire.
This is most definitely not an exploding mic with a shaped charge.
It could be something else. His shirt does move very peculiarly.
Might be something entirely different, but whatever it is, it needs to explain the inverted recoil we see in the videos.