As you know, packets flow from higher security level interfaces to lower ones by default. If you want to have an operational connection between two interfaces, your ASA must inspect the traffic so that it won't drop the connections initiated from inside.
For example, if I want ping to work I must inspect ICMP.
Here is the question: What if I have a computer outside listening on an arbitrary port, and I want to connect to that computer from inside (obviously from a randomly generated port by OS)?
Packets can get from inside to outside because of security levels, but since ASA doesn't inspect the traffic will it drop the return packets from outside to inside?