Note that on normal servers like the tf2maps there isnt alot of chaos. they have 24 players and no instant respawn. however, ukcs has 26 players and instant respawn (the crash moment was at 24). But note that at instant respawn there can be double as much going on. counting 150 dynamics being used by just weapons of alive players this gives about 150 more dynamics in your map. where normaly you might see 100 used at peak moments instant respawn can give far more.
As valve is even aware of 32 players with quite alot of engys and demoman there is a chance it goes above 400 dynamics being used by players. In your map this would have crashed far before.
To give you a hint and try what i mean with dynamics: Try on your server to spawn 31 demoman bots and yourself as demo. Let all those bots mimic you. then shoot all your stickies, then try to shoot all your grenades. In your map this guarantees a crash. This is also on goldrush and pipeline btw. However, watch the moment at when this happens. In goldrush it crashes at the 3rd grenade. In your map this is by far earlier.
And for more information:
http://forums.tf2maps.net/showthread.php?t=3924