Clojurians Log v2

Hello! I ran into some inconsistent behavior regarding update-in :jvm-opts:

$ lein update-in :jvm-opts conj -Dhi.there -- trampoline repl
;; Works correctly

$ lein update-in :jvm-opts conj -Dhi.there -- repl                                                                               
array element type mismatch

$  lein update-in :jvm-opts conj '"-Dhi.there"' -- repl
;; Works correctly   

I assume the second example fails because without the double-quoting -Dhi.there is read as a symbol, not as a string. But then why does the trampoline example work differently?