Most spacecraft (or parts thereof) intended to survive atmospheric (re-)entry use an ablative heatshield, which, when exposed to the strong aerodynamic heating of (re-)entry, gradually ablates away, expelling a layer of hot gas which shields the vehicle from the far hotter gas and plasma that would otherwise destroy it; this allows the vehicle to use the atmosphere to slow down from near-orbital speed without succumbing to the massive heating produced by hitting the atmosphere at near-orbital speed.
When a heatshield ablates away, all of the ex-heatshield gasses produced thereby are expelled forwards, in the vehicle's direction of motion; they can't escape backwards, since the capsule is in the way. This should produce a small additional braking force on top of that provided by aerodynamic drag; how much additional deceleration does the average reentry vehicle experience as a result of the recoil from the gasses expelled from the ablating heatshield?