The only way this would be connected to the accident is (a) if the transmission
cooler lines were bent/crimped due to the front end collision, thus preventing fluid flow, (b)the lines were busted or the radiator busted(which we can eliminate if there is not fluid pouring out, (c)shock damage such as force was hard enough to dislodge the fluid filter inside the pan or damage to the shift solenoids or other internal parts.
First place to start is to inspect the transmission cooler lines going to the radiator for signs of being bent or crimped and replace as needed.
If ok, then pan should be dropped to inspect the filter to see if it fell down into the pan. Reinstall as needed.
If ok, then it will require dropping the transmission and doing a teardown to find the problem and whether accident related or not. BEFORE doing this, you want to contact your insurance company on whether they will cover the teardown or not, and how to proceed as far as what shop to use, making a claim, etc.
Please remember to rate service using the rating page so that I may receive credit. Thanks