Factual error: Just before Sean Miller shoots the bookseller he takes the safety catch off the Ak-47. However, he moves the catch two clicks down and then fires the weapon on automatic. This is incorrect. For most modern weapons the safety catch feature goes safe-semi-auto, however the AK safety catch goes safe-auto-semi.
Factual error: Lymington does not contain a rising bridge, only a small ferry to the Isle of Wight. It is only a small town, and not the built up area as presented in the film (the scene was filmed at Canary Wharf in London). Interestingly, the original novel is much more accurate with Clancy explaining in precise detail the route including highway numbers and towns the van travels through to reach Lymington, and the crossing is correctly undertaken on a ferry, not a rising bridge as depicted in the film.