Clash of Kings by George R. R. Martin
The tree was slender compared to other weirwoods he had seen, no more than a sapling, yet it was growing as he watched, its limbs thickening as they reached for the sky.
While (A) was happening, (B) happened
can mean either:
(B) was some short action, that's why it makes no sense to use past continuous -> While I was reading, she called.
(B) can mean a longer action that was happening during the same time as the action . And the reason we use past simple is just for the sake of eliminating redundancy, right? Like in the sentences from the book -> Past continuous + Past simple ->
(1) It was growing as he watched (instead of was growing as he was watching)
(2) its limbs [were] thickening as they reached for the sky (instead of its limbs were thickening as they were reaching for the sky)
Bottom line: Both 1 and 2 (growing/watching and thickening/reaching) mean that all these actions were continuous in time, but we use past simple for elinimating repeats of was + Ving. Am I right with that?
Thanks in advance