At some point between the first airing and the emergence of the treknobabble interpretation obsession I'm a prime victim of, the idea developed that the pod was a danger to the ship and for this reason had to be jettisoned. But nowhere in the episode do we find dialogue suggesting that the pod would pose a risk. All the angst is about the storm, and the changes in the storm that affect Kirk's choice of jettison moment. An "egg" to be laid by the ship at the best possible moment, a moment the CO has to choose by balancing scientific gain against the risk to the deploying ship, is an attractive interpretation there.
If it were just a matter of deploying the pod so it could send back scientific readings, then it would never
be jettisoned until they knew for a fact the man was out of it.
But Kirk's testimony states that Finney was given fair warning that the jettison moment was approaching, then Kirk signaled a red alert, and very shortly thereafter pushed the button, without checking back to ensure Finney was in the clear. To me that means the safety of the ship was involved.
If Timo's reading is correct, then telemetry from a jettisoned pod must be massively important. Like save-the-ship important. So holding the pod in and of itself does not endanger the ship, but not getting telemetry from a free-flying pod does endanger the ship. That could be it after all.