Re: SSR ... SHIELD ...strategic homel ... wait
I think it is because audiences had no idea what SHIELD was in IM1, so they did that to slowly get them their. Now audiences know what SHIELD is, they used it by name in the One Shot. Possible continuity issue? Sure, but who cares. It is VERY small.
But even in IM2, Fury said Howard was a founding member. No issue there.