Scuba once bubbled...
Sorry for the confusion, I did not mention the specific scenerio this was mentioned in. Although many others are possible.
Here it is.
You come out of the cave, or your going through passages in a cave, all of sudden you check for your buddy and he's not there.
How long do you have to look for him, depending on depth, before your chances of surviving decrease greatly due to insufficient gas to complete a possible major deco obligation? How much of an additional deco obligation will you incur? How much will you have to violate?
IMO you're setting up a question that can't be answered, at least with the information given. This type of dive would be planned in fairly great detail, and there are way too many variables to make a simple answer.
A computer cannot "project". Only a reasoning human brain with the correct training could take this particular problem, with a certain set of circumstances, and make a "best case" decision on how to proceed.
Note I do not have cave training, but I think the scenerio is wide enought I can comment.
Phil