heres my . 02 how long did the truck sit? -- possibly a little air in system prob just one injector not getting fuel right away like after bleeding the fuel system
on the other hand we have a skid steer with a yanmar engine; one day at about 400 hours it blew out blue smoke like you wouldnt believe for about 15 minutes -------the last 2000 hours have been perfectly normal. i think one of the injectors may have got a little dirt inand then worked out what im saying is that unless it happens a few more times dont worry