Difference between "reliable witness / source / data / information" and "dependable witness / source / data / information"

Question

"Reliable" on britannica.com has two meanings:

1. able to be trusted to do or provide what is needed; able to be depended on:
   ...
2. able to be believed; likely to be true or correct:
   (1a) a reliable witness
   (2a) It's a rumor, but I heard it from a reliable source.
   (3a) We can't write a report without reliable data.
   (4a) We need more reliable information before we can take action.

"Dependable" on britannica.com has one meaning:

1. able to be trusted to do or provide what is needed; able to be relied on:
   ...

The first items are the same but the second item is only in the definition of "reliable".
Does it mean (1a-4a) will be incorrect with "dependable"?

my variants:
(1b) a dependable witness
(2b) It's a rumor, but I heard it from a dependable source.
(3b) We can't write a report without dependable data.
(4b) We need more dependable information before we can take action.

Are the b-variants correct?
If they are, then what's the difference between the a- and b-variants?

Answer 1

Most often a reliable witness refers to one deemed honest, one who seems as though they are offering truthful, accurate testimony; what they say comes across as forthcoming and unevasive, and their judgments seem sensible and reasonable.

A dependable witness is one the plaintiff or defense can rely upon to testify in a manner that is amenable to their goals, who doesn't say anything unexpected or counterproductive.