If a character in the game like Zevran tells us that someone can fall out of a carriage and snap their neck, we understand that bone density, muscle tenstility and overall human frailty would prevent someone from doing a backflip 20 feet in the air. Similarly, if a game tells us that exposure to lyrium is dangerous to the point of near death to touch, don't have us ingest countless amounts of the stuff on a regular basis.
It's the difference between drinking wine and jet fuel; lyrium potions are prepared in a way that makes them safe to ingest. While I hesitate to end that sentence with "duh," I would have thought it was obvious, especially since templars also consume lyrium lorewise. Also, no one jumps twenty feet into the air; that would be like jumping over two ogres on each other's shoulders (maybe more).
What about anything in DA:O made it seem like super human strength or agility was possible? Wearing armor cost extra fatigue, instead if being feather weight. Zevran trapped you by cutting down a tree to block your escape... something that could easily be jumped over by the anime ninjas we saw in DA2. The duel between Loghain and the Warden did not involve thundering crashes or insane jumps... it was a one-on-one fight that was based in the reality the game had presented us - even if that reality allowed raining fire down from the sky or healing wounds with magic.
DA2 also has insurmountable waist-high fences, it happens in almost every game that I know of.
As ridiculous as the Meredith fight was, it was still at least somewhat explainable by "crazy lyrium." To some degree, at least. Having non-magical characters like Tallis jump over walls three times taller than her is not magic, but a violations of lots of evidence the game had supplied to the contrary.
Did it ever supply that evidence, lorewise, with elves?