Could be that last round that fired was a little under charged..ie. not enough umph to fully cycle the slide which would account for the failure to feed. The 2nd cause that comes to mind, is that it may just have had a dirty chamber causing the spent case from the last round fired to stick a bit.
With my .22 lr conversion units for several 1911's, I've got to clean them each 50 rounds or so to prevent FTF problems.
Cherish our flag, honor it, defend what it stands for or get the hell out. Our Freedoms are not free, they've been paid for many times over by heros in uniform. Far better men than I, died that we could be FREE.
USAF FAC, 5th Spl Forces, An Loc, lll Corps, RVN, 69-70, Vietnam Vet '69-'73