That could very well be the case. I can't be certain. However, it's also a well-known problem in engine design. High flow rate fluid lines like propellant lines are often protected against fluid hammers. That may come in the form of a gas reservoir to absorb the pressure spike (sort of like surge suppression capacitors in electronic circuits) or as a check valve connected to a re-circulation path (like snubber/flyback diodes in electronic circuits).

The reason why I said it sounds counterintuitive is that I suspect that the flame extinction inside the combustion chamber also causes strong mechanical shocks. However, I don't know how that works and I could be mistaken.