Wouldm't surprise me
if they find the cause to be the aircraft striking an animal and the events going downhill from there.
For those who don't know DIA, it's closer to Kansas than Denver meaning it's not situated in the mountains, it's on rolling flatland about 25 miles northeast of Denver. When the construction started, one of the biggest problems was removing grass snakes and various squirrels, chipmunks, ferrets etc before they could even flatten the land to build the runways.
The airport was was their natural habitat and continues to be so it would come as no great shock if one of these varmints made an excursion to the runway and got caught up in the wheels. It would certainly explain the "bounce" the passengers felt prior to takeoff as well as the rattling and thumping on the CVR...
Having said that, 41 seconds does seem like a long time to be on a takeoff roll unless he held for traffic ahead of him to clear to his satisfaction and avoid any wake turbulance conditions. Anybody what type plane took off immediately before the CAL 737?