If you were playing it on a second gen touch, then that's the reason. I played it on my iPhone 4 and it was fine. Perfectly smooth frame rate and no crashes.
You have to remember to take everything in the rumor mine with a grain of salt. Remember that whole "Black Ops" on the iPhone coming in November 2010 debacle? Well that was fake, as are a lot of things in the rumor mine.
It'll probably come out around the same time as the avengers movie. I think they could do a decent job with it, if they don't smash it into their game model of a hack and slash with checkpoints and orbs.
Cap iOS - MADE IN CANADA I heard a studio from canada is handling Cap on iOS. I heard it was going to be quite cool. Something like Sarbakan I think the studio was named.