depending what your rates are set to, since they are running real low there, it could have just been that the server was full or something. i know when i play on dust2 (or did anyway) i couldn't get above 30 tick or less than like 25 choke just because of the intense amount of traffic through the server with 38+ people. its just how it is, you won't find a server that big that doesn't do the same thing.
its like in events with smaller maps, you'll never have less than 50 choke...its almost impossible!
set rates to cl_cmdrate 101 cl_updaterate 101 and let the server govern what the cap is (eGO is 60/66) and you'll be fine. choke otherwise is just a part of the game dependent on your connection with the server, and if that server is full or overloaded then theres really nothing that can be done about it, unless people disconnect.