Goofs - not.
"Errors made by characters (possibly deliberate errors by the filmmakers):
At the beginning of the movie, Meacham wears the eagle insignia of the full colonel. Later, he is introduced as Lt. Col. It is only after this that he begins to wear the silver oak leaf of the Lt. Col."
There is no goof here. The Lt. Col. insignia is a silver oak leaf which is worn by Bull, indicating his paygrade of 05 (Lieutenant Colonel).
In military circles, one calls a Lt[junior grade](02) 'Lieutenant' and a LCdr (Lieutenant Commander (04) 'Commander' and any admiral (Rear (Lower half, Upper half - 1 & 2 stars), Vice (3 star) and Admiral (4 star) - all 'Admiral'.
In other services, 2nd and 1st Lieutenants (01 & 02) are called 'Lieutenant' and the same with Lt Col and Colonel - 'Colonel' and so on with generals.
The 1st/2nd, Lt-, Rear/Vice are used in formal-style speech or when calling attention to another's junior status by a senior (not normally done).
The Navy captain (an 06) dressing down the (05) Lt. Col. Bull Meechum was entirely correct in his speech and the manner in which conducted.