As I recall in the early 70's there was a Northeast Trident 1E that abandoned after V1 on RWY 28 in Bilbao. There was a large hill at the end of the RWY and in the Captains opinion the a/c had stopped accelerating (big split between V1 and Vr). The result was an excursion off the side of the RWY, one main gear collapsed and no-one hurt.
Initially the captain was held at fault until investigation complete when he was completely exonerated as it was found that deep puddles on the RWY which were not notified to the crew made it a contaminated RWY and the a/c was unlikely to have ever reached Vr.
With speed trend arrows that we now have I have on occasion seen the acceleration cease momentarily during a T/O and if this was substantially below V1 at Max Wt it would certainly make me think (usually more thrust is available).
