Talking tall
Telling tall tales with the intent of obfuscation, prevarication, or evasion of inconvenient facts, regardless of whether actual malice is involved. A press secretary, either in private business or in public affairs, talks tall as a matter of standard operating procedure.
Jason was talking tall to Amber this afternoon, but she saw through his total bullshit. OR This afternoon, Senator Whatsit was talking tall in the Capitol in a way clearly at variance with the available facts.