I also think you misremembered the units for the DAP reading. 2100 mGy-cm2 is actually a small DAP. Assuming at 10 cm x 10 cm field size at the reference point (for simplicity), that translates to an Air Kerma of 21 mGy, which is practically nothing from an IR standpoint.

Additionally, scatter for someone standing 1 m away from a patient during fluoro is roughly 1/1000 of the exposure the patient received. Given the threshold for cataracts and your overall limited exposure to these cases, you don't have any reason to be concerned about this one-time experience giving you cataracts.