My main concern was if I somehow mistyped the shortened form of a word or two.  Then I would be screwed.  Imagine I somehow mistyped 'RETI' from 'retired' as 'RETR'.  Which is not impossible to do, all you need is a little bit of lack of attention and accidentally skipping the letter 'i'.  Then you are left with 11 correct short forms and 1 mistype.  When you will need to restore your wallet you will quickly find out it is not the correct one.

If you have the full words, finding out you misspelled 'retired' as 'retred' is easy.  Now if you had 12 words and they are all short form, how will you find out?