The problem is with the data, I had assumed Team1.txt held team names (even after you showed me the output frown ),
becuase it has simple numbers, $read(filename) identifier well look at the first line in the file and consider it a special case, ie: it is the number of lines in the file. This confuses the randomality of it all, and can also cause it to abort before doing the 10 loops (as per your data)

the fix, I simply used $read(filename,t) which says treat line one as plain text, i placed this on all $read to be sure.

Code:
alias draw {
  var %time = 0
  while ($read(Teams1.txt,t)) {
    var %team = $read(Teams1.txt,t) | write -dl $+ $readn Teams1.txt
    var %crew = $read(Crews1.txt,t) | write -dl $+ $readn Crews1.txt
    write loting1.txt %team voor %crew
    inc %time 1.5 | .timer 1 %time msg #woc %team 0,1is for :
    inc %time 1.5 | .timer 1 %time msg #woc ...
    inc %time 1.5 | .timer 1 %time msg #woc ..
    inc %time 1.5 | .timer 1 %time msg #woc .
    inc %time 1.5 | .timer 1 %time msg #woc %crew
    inc %time 1.5 | .timer 1 %time msg #woc _____________
    inc %time 1.5 | .timer 1 %time msg #woc 
    inc %time 0   | .timer 1 %time msg #woc 
  }
}