2004 Honda Accord - Transmission Issues

I have an Accord with about 75,500 miles on it that is having some pretty severe transmission issues. A few weeks ago, it was struck by another car while parked in a lot, causing a few thousand dollars worth of damage to the drivers’ side doors. Soon after, the car began having transmission problems.

While driving, the transmission slips in and out of gear which can be felt in the acceleration of the car and in the spontaneous spikes in RPM when it goes out of gear. No abnormal noises are heard and the car does not shake when the tranny slips. Also, it does not appear to be dependent on speed, current gear, or whether accelerating or coasting.

I have had the transmission flushed, to no avail. Currently, the insurance company is only willing to pay for any repairs to the tranny if the issue can be firmly linked to the accident; therefore I turn to the Car Talk community for some advice. What are the odds that the collision is the source of the problem? What might the actual problem with the transmission be? Any insight that can be provided is incredibly appreciated. Thank you.

Manual or automatic trans?
If manual did you park it in gear?
If it was parked in gear the collision could definitely damage the trans.

Automatic trans. In park with the e-brake on at time of collision.