Earlier on p. 16, Hal notes, "[a]t the only other emergency room I have ever been in, almost exactly one year back...". We don't know the exact time of this visit, but signs point to it being the Friday or Saturday of the big fundraising tournament when the AFR were due to intercept the Quebec Jr. Wightman and Jr. Davis cup squads and then storm ETA. I.e., soon after Hal's last chronological scene before the Year of Glad scene.
How he comes to end up there, the ER, is also unclear, but this is the same weekend when he, Pemulis, and a couple others are due to drop DMZ. (p. 217) Though we don't know if they go through with it. Hal in particular is having reservations after he quits smoking pot. (En. 321) And Pemulis may or may not still be on campus at this point.
More thoughts from others here:
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