If there is a reduction in buoyancy whilst the Fiobuoy is submerged, could the rope slip?

Whilst the Fiobuoy is submerged, the rope (held securely by the jaw and pin), sits between the Fiobuoy’s handles. In order for it to slip, there would need to be a significant and sustained force pushed downwards directly on the Fiobuoy. This force would need to counter the Fiobuoy’s own bouyancy of 3.5 or 8kg.

Although unlikely, if this were to occur, the worst case scenario would see the rope merely slip between the next handles, remaining tethered and the jaws securely closed.