Why does this script not work when run with osascript cli?

Question

I wrote the following to interface with geektool to display a list of todo's on my desktop (i'm sure it's been done elsewhere, but I wanted to try it myself). I had it working fine until I tried ordering the output to place the highest priority items at the top of the list. The following code works properly during development in Script Editor, but when geektool launches the command using osascript ~/Library/Scripts/todos.scpt it only displays the initial "TODOS:" without displaying the rest of the info. Searching the Applescript Release notes, I found that some versions of Applescript 1.8 had issues with null characters when using the osascript cli, however, I'm running 1.10.7 so it shouldn't be an issue (and I'm not sure how to check for null characters in Applescript even if it were). Anybody have any ideas on what's going on here?
set output to {"TODOS:
set highpri to {}
set medium to {}
set low to {}
set nada to {}
tell application "iCal"
repeat with i in calendars
repeat with j in todos of i
if (completion date of j as string) is equal to "" then
if priority of j as string is equal to "high priority" then
copy summary of j & "
" to end of highpri
end if
if priority of j as string is equal to "medium priority" then
copy summary of j & "
" to end of medium
end if
if priority of j as string is equal to "low priority" then
copy summary of j & "
" to end of low
end if
if priority of j as string is equal to "no priority" then
copy summary of j & "
" to end of nada
end if
end if
end repeat
end repeat
end tell
return (output & highpri & medium & low & nada) as string

Answer 1

well, i'd been pulling my hair out for quite a while with this and decided it was time to ask for help, but I thought I'd give it one last shot and found a resolution almost immediately. I figured that problem had to be caused by the way applescript was concatenating the lists, so I got rid of the lists completely and it still wouldn't work. This convinced me that it must be newline related since that was the only special character left in the string. I opened up the script in vi, but the default compiled script format is not human readable. The osascript man page indicated that it would accept both compiled and text scripts, so I gave it a try, and osascript handled the raw text file wonderfully.