denver broncos ' aqib talib and brother are being investigated for assault .
talibs were reportedly involved in physical fight at club luxx in dallas .
the vehicles they left in , a range rover and a jaguar , were impounded .
man who called police said someone aimed at him before firing gun in air .
dallas club manager refuted assault claim and said there was no gun shot .
talib and mother were charged with assault with a deadly weapon in 2011 .
they reportedly both fired multiple shots at the boyfriend of talib 's sister .
the 29-year-old had charges dropped after that incident involving two guns .