Strange that I can make it happen like this and not you... well it looks like I could be on the wrong track then [...]
Gren is very much on the right track here. I've been thinking that it had more to do with length of playtime than action sequence as far as repeatability (which is why savegames never seem to repeat the bug immediately), but hadn't found a reliable way of measuring playtime to get to this bug.
Gren's method (just hit retry a bunch) worked for me - between the 7th and 9th retry each time. In testing, I took it one step further and found that calling I_AddInvList (The function where the crash message is) 1025 times is what makes it crash.
Steps:
Navigate to your ufoai folder in terminal.
Type:
gdb ufo
break I_AddInvList
ignore 1 1024
run
Load a campaign and start a mission. Send out the drop team and retry the mission until the breakpoint is reached, and when you hit continue, the program will exit with the error.
To playtesters who don't want to encounter this bug: Save, quit, and reload the game after 3-5 missions, especially if you retried them.