This isn't a huge issue, but using splendid cam's aerial and thermal capabilities vastly speeds up a mission makers ability to test missions and see that AI and other objects are in position and behaving accordingly without moving the player.
There are a number of other issues that I have seen reported with external scripts and functions causing bugs when splendid cam is in use. (I would site sources, but just look around the feedback tracker and you will find a few) It is possible that splendid cam works in a non scheduled environment while the external scripts run in a scheduled environment. When splendid cam opens the exit dialog box it could relegate splendid cams thread(s) to a lower priority than external scripts preventing it from getting any time on the processor. This would cause all your input to 'cancel' or 'proceed with exiting' to effectively fall on deaf ears as the data is collected, but the processor never gets a chance to process it. In other bugs it could be the opposite happening, where splendid cam gets too much priority, or other thread priority problems. This seems likely from my understanding of threading with scheduled and non scheduled code (internal scripts versus external scripts). (source: http://killzonekid.com/arma-scripting-tutorials-code-performance/)
The Steps to Reproduce section is written so that those with no coding experience can reproduce it. Experienced modders, coders and BI developers, hopefully you understand.