Strangely enough, two recent dismissals of Justin Langer that immediately spring to mind were of Harmison doing precisely that - and the Michael Clarke slower ball will achieve 'Legend' status in years to come.
What you argue is impossible to quantify, of course, without a fair bit of digging - and I really can't justify the time to go back and review all the dismissals attributed to both pacemen (although it would give me a chance to watch the whole series again, which is no bad thing). I will agree, though, that both Lee and Harmison tend to be unsure of the length they should be bowling quite often, and over-do the short stuff.
Taking the recent Ashes series and the (ahem) Super Series test matches as an example, Harmison took 21 wickets, of which a very high proportion were from pitched-up deliveries, and only a couple (IIRC) were from batsmen taking evasive action or fending throat balls away. Lee has a similar number of wickets, and a quick examination shows a reasonably high proportion of bowled, LBW and caught behind (not that that means a lot, going by the howls of protest at the time regarding the umpiring, of course).