strace of SHIFT + DELETE (no prompt but file deleted):

[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 3995) = 1 ([{fd=16, revents=POLLIN}])
[pid  3466] ioctl(16, FIONREAD, [32])   = 0
[pid  3466] write(10, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3466] poll([{fd=10, events=POLLIN}], 1, 10) = 1 ([{fd=10, revents=POLLIN}])
[pid  3466] poll([{fd=10, events=POLLIN}], 1, 10) = 1 ([{fd=10, revents=POLLIN}])
[pid  3466] read(10, "\1\0\0\0\0\0\0\0", 16) = 8
[pid  3466] poll([{fd=10, events=POLLIN}], 1, 10) = 0 (Timeout)
[pid  3466] read(10, 0x7f91117fdb10, 16) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3466] write(10, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 3135) = 2 ([{fd=10, revents=POLLIN}, {fd=16, revents=POLLIN}])
[pid  3466] ioctl(16, FIONREAD, [32])   = 0
[pid  3466] write(10, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3466] read(16, "\2\0\0\0\0\2\0\0\0\0\0\0\20\0\0\0New File\0\0\0\0\0\0\0\0", 1024) = 32
[pid  3466] read(16, 0x7f9104011580, 1024) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3466] write(10, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 1000) = 1 ([{fd=10, revents=POLLIN}])
[pid  3466] read(10, "\3\0\0\0\0\0\0\0", 16) = 8
[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 1000) = 0 (Timeout)
[pid  3466] read(10, 0x7f91117fdb10, 16) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3466] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] <... poll resumed> )        = 1 ([{fd=4, revents=POLLIN}])
[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 2133 <unfinished ...>
[pid  3063] read(4, "\1\0\0\0\0\0\0\0", 16) = 8
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 30133) = 1 ([{fd=5, revents=POLLIN}])
[pid  3063] read(4, 0x7fffdccefaa0, 16) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(5, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1;\0\0\0\21\0\0\0\211\0\0\0\1\1o\0\25\0\0\0/org/freedesktop/DBus\0\0\0\2\1s\0\24\0\0\0org.freedesktop.DBus\0\0\0\0\3\1s\0\20\0\0\0NameOwnerChanged\0\0\0\0\0\0\0\0\7\1s\0\24\0\0\0org.freedesktop.DBus\0\0\0\0\10\1g\0\3sss\0\0\0\0\0\0\0\0!\0\0\0org.freedesktop.thumbnails.Cache1\0\0\0\0\0\0\0\0\0\0\0\6\0\0\0:1.129\0", 2048}], msg_controllen=0, msg_flags=MSG_CMSG_CLOEXEC}, MSG_CMSG_CLOEXEC) = 219
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(5, 0x7fffdccef910, MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 0) = 1 ([{fd=4, revents=POLLIN}])
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 30059) = 1 ([{fd=4, revents=POLLIN}])
[pid  3063] read(4, "\3\0\0\0\0\0\0\0", 16) = 8
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 30059) = 1 ([{fd=5, revents=POLLIN}])
[pid  3063] read(4, 0x7fffdccefaa0, 16) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(5, {msg_name(0)=NULL, msg_iov(1)=[{"l\4\1\1?\0\0\0\24\0\0\0\211\0\0\0\1\1o\0\25\0\0\0/org/freedesktop/DBus\0\0\0\2\1s\0\24\0\0\0org.freedesktop.DBus\0\0\0\0\3\1s\0\20\0\0\0NameOwnerChanged\0\0\0\0\0\0\0\0\7\1s\0\24\0\0\0org.freedesktop.DBus\0\0\0\0\10\1g\0\3sss\0\0\0\0\0\0\0\0'\0\0\0org.freedesktop.thumbnails.Thumbnailer1\0\0\0\0\0\0\0\0\0\6\0\0\0:1.129\0", 2048}], msg_controllen=0, msg_flags=MSG_CMSG_CLOEXEC}, MSG_CMSG_CLOEXEC) = 223
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(5, 0x7fffdccef910, MSG_CMSG_CLOEXEC) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] write(4, "\1\0\0\0\0\0\0\0", 8) = 8
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 0) = 1 ([{fd=4, revents=POLLIN}])
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 30048) = 1 ([{fd=4, revents=POLLIN}])
[pid  3063] read(4, "\3\0\0\0\0\0\0\0", 16) = 8
[pid  3063] recvmsg(3, 0x7fffdccef900, 0) = -1 EAGAIN (Resource temporarily unavailable)
[pid  3063] poll([{fd=4, events=POLLIN}, {fd=3, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}], 5, 30048 <unfinished ...>
[pid  3466] <... poll resumed> )        = 0 (Timeout)

SHIFT + DELETE on a folder with contents (fails to delete folder):

[pid  3466] poll([{fd=10, events=POLLIN}, {fd=16, events=POLLIN}], 2, 3997 <unfinished ...>
[pid  5368] <... restart_syscall resumed> ) = -1 ETIMEDOUT (Connection timed out)
[pid  5368] futex(0x7f911e9b8b40, FUTEX_WAKE_PRIVATE, 1) = 0
[pid  5368] madvise(0x7f9108017000, 8368128, MADV_DONTNEED) = 0
[pid  5368] _exit(0)                    = ?
[pid  5368] +++ exited with 0 +++